detailed study of PINEAL AN ENIGMA OR A REALITY

PINEAL AN ENIGMA

1. PINEAL AN ENIGMA OR REALITY
S.K. Garg

2. Major endocrine glands

3. •The pineal a neurochemical transducer of
photoperiodic information has been linked to
several behavioural and physiologcal functions
•During vertebrate evolution it has
transformed from a mere photosensory
organ to an endocrine gland-releases
primarily melatonin, into circulation (into the
cerebro-spinal fluid)
•The pineal gland is able to measure daylength
and adjust secretion of melatonin

4. •The pineal gland is one of the smallest organs in
the body, plays a large role in directing the
functions of several systems in the body,
including the reproductive system
•Its atrophy can disrupt these functions.
•It is unique in the anatomy of the
human brain in being a structure not
duplicated on the right and left sides.

5. Similarities between pineal and eyes
•Both the pineal and the retina make melatonin and
contains visual pigments (porphyropsin and rhodopsin)
•Pineal photoreceptors resembles to the cones of
retina
•Pineal also makes a number of proteins that were
thought to be made only by the eye that are necessary
for processing light.
•Like the pineal, the eye also serves as one of the
body's time-keeping mechanisms.
•Because of so many similarities between the eye and
the pineal, scientists hope to use a person's pineal as a
source of genetic spare parts to treat some eye ailments.

6. The Pineal
The pineal gland also called
1. Pineal body,
2. Corpus pineale,
3. Epiphysis cerebri,
4. epiphysis
•It is a small pinecone-shaped endocrine gland
•located at the posterior portion of the third ventricle
of the brain, near the center of the brain, between the
two hemispheres, tucked in a groove where the two
rounded thalamic bodies join.

8. Showing location of Pineal in human brain
•Small structure
•Located between
the two cerebral
hemispheres
•Attached to upper
part of thalamus

9. History-Mystery-Enigma
•The tiny, deeply buried pineal gland has
mystified researchers for centuries.
•Rene Descartes, one of the great thinkers of the
17th century, credited the pineal gland with being:
1.The seat of the rational soul,
2.Connection point between mind and body.
3. Occasionally associated with telepathy and/or
enlightenment.
4.Sometimes it's referred to as a "Third Eye
Inner eye or eye of the soul,“
in occult religions also Called as brow chakra in yoga,

10. Seat of the rational soul

11. •It is located on the "sixth chakra" on the
forehead, between the eyebrows.
• In India, deities and saints are often
depicted with the third eye: the round
mark that you see on their forehead
between their eyes.

12. Lord Shiva showing third eye

13. •It is believed by some people that it is a dormant
organ can be awakened to enable telepathic
communications.
•Consult your pineal gland" is a common saying in
Discordianism, a religion which emphasizes
chaos.
•Some Discordians seem to regard the pineal gland
as the source of answers to life's most difficult
questions.
•A connection between the material and
immaterial world.

14. Psychedelic chemical
Dimethyltryptamine (DMT)
•Pineal gland manufactures trace amounts of the
psychedelic (mood altering, hallucinogic)
chemical Dimethyltryptamine, or DMT.
•This endogeous chemical in the human brain is
believed to play a role in dreaming and
possibly near-death experiences and other
mystical states.
•It has been suggested by the researcher Jace
Callaway that DMT is connected with visual
dreaming

15. •In some cases it was also referred to as "the
atrophied third eye".
•It has also been suggested that the third eye
(Anjana) physically resides at this location
between the two hemispheres of the brain.

16. •The pineal gland was once considered a vestigial
organ, comparable to the appendix
•After being labeled as a vestigial organ for quite
sometime, scientists have now shed new light into
its role as the
•Body’s light meter (By the light meter means its
role in the non-visual functions of light).
•The pineal gland is an enigma within the central
nervous system that appears to exert tremendous
control over the homeostatic mechanisms of the
body.

17. In 1905, Studnicka established that
phylogenetically the pineal gland is derived
from a photoreceptor organ, but its function
remained unknown
According to a recent study of Gottfriedde Puruker
(2011) that The pineal gland vibrates gently
when ever we have a hunch (feeling or guess), It
vibrates more strongly when we have some
intuition or a sudden flash of intuitive
understanding

18. •The pineal organ is present in most
vertebrates, however,It is absent in:
1.Lancet
2.Hagfish (Myxinoid Cyclostomes)
3.Crocodiles
4.In two chondrichthyes-Torpedo ocellata and
Torpedo marmorata.
5.Several mammals like whales and edentates
6.It is small in size in elephants and rhinoceros

19. In animals, the pineal gland appears to play a
major role in
•Hibernation
•Metabolism
•sexual development
•Seasonal breeding
The pineal gland and the hormone it
produces, melatonin, regulate
• Circadian rhythms,
• Sleep-wake cycles,
• Thermal and immunologic systems,
• Reproductive capability

20. Human pineal
•The human pineal gland grows in size until about
1–2 years of age
• Its weight increases gradually from puberty
onwards
•In normal humans it starts shrinking from the age
of 25, slowly losing its ability to control hormones in
the body and contributing to the process of aging.
.

21. •The Pineal gland is the first gland developed in
your body, and appears in Homo sapiens a mere
3 weeks after conception. There are five things
that the Pineal gland is responsible for:
•Inner Eye – Sensing light and darkness
•Biological Clock – Tell our bodies when to do its
functions
•Pacemaker – Sets the pace or rhythm for the
body
•Compass – Helps us orient ourselves
•Production and Secretion of 2 biologically key
hormones:Serotonin and melatonin

22. •In humans, it induces an almost irresistible
urge to sleep.
•Its primary function is to signal the day length to
the supra chiasmatic nucleus (SCN), so that it can
synchronise the day/night cycle with:
•Endocrine rhythms
•Body temperature
•Glucose homeostasis
•Lipogenesis
•Locomotor activity
• 

23. contd
•Human research has demonstrated that the
pineal gland also plays a role in
•Sleep disturbances
•Menstrual and reproductive irregularities,
•Psychological and behavioral disorders,
•May even serve as a tumor inhibitory gland.
•Now it is apparent that the pineal gland and
melatonin have widespread effects and
optimal functioning of the pineal gland is
essential to our well-being

24. Antigonadotropic
•At the beginning of the 20th century the
physiological role of the pineal gland was studied.
Heubner presented the case of three girls with
pineal tumors and precocious puberty.
•He concluded that the destruction of the pineal by
the tumor had prevented the normal production of
an antigonadotropic pineal hormone and raised
the hypothesis that the pineal maybe controlling
the onset of puberty.
•The link between the pineal and reproduction
was thus established.

25. In children
•The invasion of the gland in children, by
pathological growths which destroy the
glandular tissue, results in accelerated
development of the sexual organs, increased
growth of the skeleton and precocious
mentality
•It seems probable that the gland furnishes an
internal secretion in children that inhibits the
development of the reproductive glands

26. •The pineal gland is large in children, but
shrinks at puberty.
•The abundant melatonin levels in children are
believed to inhibit sexual development

•Pineal tumors have been linked with precocious
puberty
•When puberty arrives, melatonin production is
reduced.

27. Calcification of the pineal gland  
Damage to the gland by calcification, causes
defective sense of direction
In Africans it is 5-15%; Asians
­15-25%; Europeans ­
60-80%
•Causes of Calcification: The gland accumulates
calcium phosphate crystals, becomes hardened,
and loses much of its functionality
What causes calcification of the pineal gland?
The possibilities include:
Fluoride, Artificial sweeteners ,Radiation from
mobile/cell phones
 

28. •Approximately 60 years ago, it was
discovered that the pineal gland was not a
decayed remnant of the primitive brain,
but, in fact, produces a hormone--
melatonin that serves a vital function in
the animal kingdom

29. Discovery-melatonin
In 1943, Bargman suggested that the endocrine
function of the pineal gland, regulated by
light, via the central nervous system.
It was only after the 1960s that scientist discovered
that the pineal gland is responsible for the
production of melatonin, which is regulated in a
circadian rhythm.
It was Prof. Lerner a dermatologist who isolated
melatonin in 1958
Melatonin is a derivative of the amino acid
tryptophan, which also has other functions in the
Central Nervous System

30. It was further discovered that
•The pineal gland releases melatonin only when
two conditions are satisfied:
•It is the "biological night".
•Light levels are low.
The production of melatonin by the pineal gland
is stimulated by darkness and inhibited by light
In the absence of light or melanopsin, melatonin is
produced by the pineal gland
The retina detects the light, and directly signals and
entrains the suprachiasmatic nucleus (SCN).

31. Melatonin controls sleepiness and
wakefulness, or modulation of sleep
patterns. In this way, melatonin maintains
the circadian rhythm (the sleep-wake
cycle).
It also helps the body to convert signals from
the nervous system to signals in the
endocrine system
•Physiologically, in conjunction with the
hypothalamus it controls many functions

32. MELATONIN SYNTHESIS

33. Melatonin Synthesis
In mammals AND OTHER ANIMALS the pineal
gland is responsible for the synthesis of the
hormone melatonin in response to signals
originating from the endogenous clock located in
the hypothalamic suprachiasmatic nucleus (SCN).
•Presence of even little light can switch off
melatonin production in the pineal via this
pathway
 

34. •Melatoninis N-acetyl-5-methoxy-tryptamine, a
derivative of the amino acid tryptophan
•Within the pineal gland, serotonin (the precursor)
is acetylated and then methylated to yield
melatonin, produced in the pineal parenchyma
from serotonin by two enzymes
•Arylalkylamine N-acetyltransferase (AANAT) and
Hydroxy indole- O-methyl transferase (HIOMT),
are necessary for melatonin biosynthesis secreted
into the blood and CSF

35. The precursor to melatonin is serotonin, a
neurotransmitter that itself is derived from the amino acid
tryptophan. Within the pineal gland, serotonin
(precursor) is acetylated and then methylated to yield
melatonin.

36. Photoperiodic regulation of HIOMT activity in rat pineal gland
( SP=Short photoperiod,LP=Long hotoperiod,LL=Continuous light

37. Showing connection of pineal and eye

38. Pathway of light

39. •In reality, the pineal gland is an essentially part
of the visual system.
• In mammals it responds indirectly to light
because it receives messages along fibers from
nerve cells of the suprachiasmatic nucleus of the
hypothalamus, which themselves receive signals
from the eye via fibers of the optic nerve. The
suprachiasmatic nucleus is considered to be
the body's major rhythm–generating centre
— the heart of the body clock or biological
clock.

40. Pathway of light to pineal

Light
Suprachiasmatic Nucleus (Hypothalamus)

Nerve Cells/fibers Pineal

Effector Organs


Eye
Optic nerve
fibres

41. Now we’re just beginning to understand the
importance of melatonin in the human body
1.Control of seasonal reproduction
2. Modulation of sleep processes
3. Influences bone growth and osteoporosis
4.Ability to neutralize free radicals which leads to a
reduction in cataract formation,
5. Reduces oxidative stress due to exposure to
hyperbaric hyperoxia,
6. Ameliorating hyperthyroidism
7.Abating the toxicity of sepsis and septic shock.

42. Melatonin and Epilepsy
•German researchers have found that injections of
melatonin helped epileptic children sleep better
and reduced the frequency of epileptic attacks.
•Most research with melatonin and epilepsy has
been done with children with severe epilepsy and
other neurological problems
•Melatonin reduces prostate cancer cell
growth-
•Men with benign prostatic enlargement who took
2 mg of melatonin at night , had less nocturia
(getting up at night to urinate).

43. . Melatonin Affects Male Fertility--low melatonin
levels in men can reduce their fertility and may
even cause infertility.
•Melatonin and the Ovaries-Woo et al (1986)
found that melatonin acts as a modulator of
ovarian function.

44. Melatonin and cancer
•Melatonin and Breast Cancer- women with the
highest melatonin levels had the lowest risk of
breast cancer.
•Sleep Duration and Breast Cancer: A
Prospective Cohort Study- women who slept 9
hours or longer had a 30 percent decreased risk
of breast cancer compared to women who slept
less than six hours a night.
•Night Shift work can cause low melatonin and
leading increased risk of cancer.
•WHO, officially classified working night shifts as a
“probable” carcinogen.

45. Breast cancer
•Female night-shift workers -have about a 50 percent
greater risk of developing breast cancer.
•They found a significant correlation—the brighter
the lights, the higher the risk of breast cancer:
•when they compared communities with the lowest
amount of light to average communities, they found
37 percent higher breast cancer rates, and communities
with the highest amount of lighting had a whopping 64
percent higher rate than the lowest amount of light.
•This also correlates well with the findings that working
night shifts in a brightly lit environment leads to estrogen
dominance and a 60 percent increase in the risk of
breast cancer.

46. Rotating shifts
•It is very difficult for the circadian system to
adapt to any component schedules, thus
causing a permanent Jet-lag. This results in:
•Increased cancer risk
•Metabolic disturbance
•Increased incidence of irritable bowel
syndrome
•Increased risk of type 2 diabetes
•Increased risk of accidents

47. Melatonin and Obesity
•Based on animal models, studies have shown
that melatonin plays a role in preventing the
development of obesity. melatonin helps
regulate seasonal body weight and energy
balance.
• Scientists at the University of Granada proved
“that melatonin helps control weight gain,
even without reducing food intake and
•improves blood lipid profile by reducing
triglycerides,
•increasing HDL cholesterol and lowering LDL
cholesterol.

48. •Scientists believe that melatonin may help
prevent cardiovascular diseases associated
with obesity and dyslipidemia. (increase of
lipids/fats in blood-cholesterol etc)
•If these findings are confirmed in humans,
administration of melatonin and the ingestion
of food containing it could be a tool to help
combat obesity and risk factors associated with
it.
(Pineapples,Bananas,Oranges,Oats,Sweet
corn. Rice,Tomatoes and Barley)

49. Cases of attaining early puberty
•We know that the with changing life style-age of attaing
puberty is decreasing-why?
•Increased exposure to lighting, decreased levels of
melatonin etc.
•Jennifer Luke of the UK discovered that the pineal gland is
a major site of fluoride accumulation within the body - with
higher concentrations of fluoride than either teeth or bone.
The accumulation of fluoride in the pineal gland can
reduce the gland's synthesis of melatonin, a hormone
that helps regulate the onset of puberty. Fluoride-treated
animals were found to have reduced levels of circulating
melatonin and an earlier onset puberty than untreated
animals.

50. Fluoride and Earlier Puberty in Girls
•In the United States, children are reaching the
age of puberty at earlier ages than in the past —
a trend that carries health consequences,
including a heightened risk for breast cancer.
•Girls living in a fluoridated community reached
puberty five months earlier than girls living in a
non-fluoridated community.
 
•Some evidence indicates that fluoride, via its
effect on the pineal, could be a contributing
cause to this trend.

51. •Postmenarcheal girls were seen at
younger ages in the higher fluoride town

52. •In animal studies, for example, fluoride exposure
has been found to cause a decrease in the
amount of circulating melatonin and lead to an
accelerated sexual maturation in females. (Luke
2001).
•Melatonin maintains the body’s circadian
rhythm (sleep-wake cycle), regulates the
onset of puberty in females, and helps
protect the body from cell damage caused by
free radicals

53. How to Optimize Your Melatonin Levels
•Avoid watching TV or using your computer in the
evening, at least an hour or so before going to bed
 
•Make sure you get BRIGHT sun exposure regularly
•Sleep in complete darkness, or as close to it as
possible
•Install a low-wattage yellow, orange or red light bulb
if you need a source of light for navigation at night
•Studies show that the optimal room temperature for
sleep
 is between 60 to 68 degrees.
•Be mindful of
  electromagnetic fields in your
bedroom

54. •The most important way to maintain
normal melatonin levels is to get plenty
of sleep in a dark room.
•Melatonin is found in small amounts in some
fruits and vegetables such as:
Mustard, Goji Berries, almonds, sunflower
seeds, cardamom, fennel, coriander and
cherries. Their regular use could help to control
weight gain and prevent cardiovascular diseases
associated with obesity and dyslipidemia.

55. How we can activate our Pineal gland?
•Sunlight – It is very important for eumelanated
people to spend time in natural light.
•Chlorophyll – In the form of green vegetables, raw
is best
•Sleep – Before midnight, as we see a significant
spike in melanin at that time
•Water – Another purifier for the body it helps
release toxins
•(Good) Music & other strong vibratory frequencies
– this is particularly important for the Pineal gland.

57. •Pineal functions in lower vertebrates

58. During vertebrate evolution it has transformed
from a mere photosensory organ to an
endocrine gland-releases primarily melatonin,
into circulation (into the cerebro-spinal fluid)
•The pineal gland is able to measure daylength and
adjust secretion of melatonin
•It is directly a photosensory organ contains
photosensory cells similar to the cones of
retina.
In the lower vertebrates it is a hollow sac, situated on
the roof of the diencephalon. Its cavity is in open
communication with the IIIrd ventricle of the brain.

59. Dorsal view of head of the catfish
(note:partially depigmented window in the head-A median
pineal fontanelle in the frontals

60. Dissection showing pineal location

61. Digrammatic sketch

62. •How fishes or other animals responds to seasonal
changes in photic input and temperature?
1.Eyes
2.Pineal
3.Thermoreceptors
4.Deep encephalic photoreceptors
In Teleost fish, Development, growth and reproduction
are influenced by the daily and seasonal variations of
photoperiod and temperature.
Early in vivo studies indicated that pineal gland mediates
the effects of these external factors, most probably
through the rhythmic production of melatonin

63. •Photoperiodic effects in fish might be mediated via
the pineal gland- which is a photoreceptive and
neuroendocrine structure
-In catfish also it is a photosensory and neuroendocrine
structure, conveys photoperiod information to the
brain

64. Pineal gland and melatonin have been shown to
be involved in the following functions:
1.Circadian locomotor activity
2.Skin pigmentation and skeletal development
3.Demand feeding
4.Growth and Reproduction
5.Plasma electrolyte balance
6.Seasonal thermoregulation
7.Body fat content and liver glycogen levels etc.

65. •Seasonality and reproduction

67. Ovarian cycle

68. Testicular cycle

69. Role of pineal in reproduction
•Pineal can be antigonadal or progonadal
depending upon the season, sex and
reproductive state of the animal.
•Experiments were conducted and catfish
were exposed to different light regimes
during different phases of the annual
reproductive cycle

70. Effect of Pinealectomy on the ovary and vitellogenin
level in the catfish, H. fossilis, during the
postspawning period (80days)
Duration of Duration of
exposure exposure
daysdays
TreatmentTreatment GSIGSI VitellogeninVitellogenin
Levels (µg/ml serum)Levels (µg/ml serum)
00
8080
Initial control Initial control 0.520.52±0.08±0.08 --
Sham operatedSham operated 4.754.75±1.11±1.11
dd
32.1432.14±2.52±2.52
aa
PinealectomizedPinealectomized 1.711.71±0.14±0.14
ee
63.3363.33±9.02±9.02
bb
Blinded-pinealectomizedBlinded-pinealectomized 3.363.36±0.87±0.87 28.3328.33±4.22±4.22
BlindedBlinded 4.064.06±0.87±0.87 51.7551.75±7.25±7.25
Intact control Intact control 4.804.80±1.00±1.00 30.1530.15±1.9±1.9
100100
Sham-operatedSham-operated 7.017.01±1.06±1.06 52.0052.00±4.29±4.29
PinealectomizedPinealectomized 4.014.01±0.61±0.61
kk
37.5037.50±1.13±1.13
Blinded-pinealectomizedBlinded-pinealectomized 6.676.67±0.73±0.73 70.1770.17±±1.201.20
BlindedBlinded 7.247.24±0.81±0.81 38.0038.00±1.6±1.6
Intact controlIntact control 7.037.03±0.51±0.51 50.0050.00±1.5±1.5

71. Effect of Pinealectomy on the ovary and vitellogenin levels of the
catfish, H. fossilis (60 days treatment)-Preparatory period
Photoperiod Treatment GSI Vitellogenin
Levels (µg/ml serum)
LD 14:10
Initial control (0days) 0.64±0.55 -
Sham operated 6.33±0.91 40.43±4.64
Pinealectomized 9.64±0.94 58.43±5.64
Blinded-pinealectomized 8.88±0.90 69.00±7.97
Blinded 7.97±0.94 71.50±10.69
Intact control 6.41±0.81 45.50±5.12
LD 9:15
Sham-operated 9.16±0.69 68.00±8.05
Pinealectomized 8.60±1.64 55.83±4.68
Blinded-pinealectomized 6.74±0.63 53.08±11.6
BlindedBlinded 12.39±0.7712.39±0.77 67.67±6.2567.67±6.25
Intact controlIntact control 8.87±1.008.87±1.00 70.00±8.0070.00±8.00

72. Exposed to continuous Darkness (DD) at 25
o
C during
the postspawning period.
Duration of Duration of
exposure exposure
(days)(days)
TreatmentTreatment GSIGSI VitellogeninVitellogenin
Levels (µg/ml serum)Levels (µg/ml serum)
00
6060
Initial control Initial control 0.520.52±0.08±0.08 --
Sham operatedSham operated 4.144.14±0.72±0.72
aa
272.86272.86±15.82±15.82
PinealectomizedPinealectomized1.911.91±0.54±0.54
bb
33.3333.33±6.67±6.67
Blinded-Blinded-
pinealectomizedpinealectomized
1.401.40±0.27±0.27
cc
54.2954.29±21.11±21.11
BlindedBlinded 2.262.26±0.36±0.3640.0040.00±8.71±8.71
Intact control Intact control 4.004.00±0.60±0.60
cc
280.00280.00±1.35±1.35

73. Effect of Pinealectomyon the ovary and vitellogenin
level in the catfish, H. fossilis,exposed to continuous
light (LL) at 25
o
C during the postspawning period
(80days)
Duration of Duration of
exposure exposure
daysdays
TreatmentTreatment GSIGSI VitellogeninVitellogenin
Levels (µg/ml serum)Levels (µg/ml serum)
00
8080
Initial control Initial control 0.520.52±0.08±0.08 --
Sham operatedSham operated 4.754.75±1.11±1.11
dd
32.1432.14±2.52±2.52
aa
PinealectomizedPinealectomized 1.711.71±0.14±0.14
ee
63.3363.33±9.02±9.02
bb
Blinded-pinealectomizedBlinded-pinealectomized 3.363.36±0.87±0.87 28.3328.33±4.22±4.22
BlindedBlinded 4.064.06±0.87±0.87 51.7551.75±7.25±7.25
Intact control Intact control 4.804.80±1.00±1.00 30.1530.15±1.9±1.9
100100
Sham-operatedSham-operated 7.017.01±1.06±1.06 52.0052.00±4.29±4.29
PinealectomizedPinealectomized 4.014.01±0.61±0.61
kk
37.5037.50±1.13±1.13
Blinded-pinealectomizedBlinded-pinealectomized 6.676.67±0.73±0.73 70.1770.17±±1.201.20
BlindedBlinded 7.247.24±0.81±0.81 38.0038.00±1.6±1.6
Intact controlIntact control 7.037.03±0.51±0.51 50.0050.00±1.5±1.5

75. Photoperiod regulates the reproductive
cyclicity
-Synchronizes reproductive functions
-Without light reproductive rhythm still
occurs,
however, efficiency is impaired

76. Conclusions on the role of Pineal in
Reproduction
•1. Ovarian recrudescence and vitellogenin synthesis
are accelerated after pinealectomy in fish exposed to LD
9:15 at 25°C
•2. Ovarian recrudescence and vitellogenin synthesis is
delayed after pinealectomy in fish exposed to
LD 14:10
LD 12:12
LD 6:18
LL or DD
•3. Since estrogen dependent vitellogenin levels
fluctuate as a result of Pinealectomy- suggesting an
influence on hypothalamo-hypophyseal gonadal
axis.

77. Effect of DD & LL on pineal ultrastructure
•Exposure of pineal to DD stimulates its
activities by increasing the volume of
nucleus and nucleolus, indicating enhance
in protein synthesis,
•Exposure to LL inhibits its activity by
decreasing the volume of nucleus and
nucleolus

81. Effect of melatonin treatment on gonadal
activity in H. fossilis (LD 12:12 at 25
o
c)
TreatmentTreatment GSIGSI GSI (Recovery - 20 days)GSI (Recovery - 20 days)
Initial controlInitial control 2.82.8±0.3±0.3 ______
Saline controlSaline control 6.86.8±1.5±1.5 6.56.5±1.2±1.2
Melatonin Melatonin
20µg/day20µg/day
3.23.2±0.3±0.3 7.57.5±1.3±1.3
Melatonin100µg/Melatonin100µg/
dayday
1.01.0±0.02±0.02 8.58.5±1.6±1.6
Experiment I (Prespawning Period) 20 Day Treatment

82. •-Treatment with melatonin significantly
inhibits vitellogenin synthesis,results in the
regression of ovary
•-Induces follicular atresia
•-Reduces number of gonadotrops and
gonadotropin synthesis
•-Cessation of melatonin treatment results in
restoration of ovarian and pituitary activity

84. •Role of pineal in circadian locomotor
rhythms in catfish

85. Role of pineal in circadian locomotor
rhythms in catfish

86. CIRCADIAN LOCOMOTOR RHYTHMS

87. CIRCADIAN LOCOMOTOR RHYTHMS

88. From these studies it is clear that removal of pineal
changes the period length.
•In catfish locomotory rhythms becomes free
running and
•pinealectomy induces arhthymicity.
• Fishes are able to entrain their diurnal locomotor
activity to an external light- dark cycle after
removal of visual input (blinding), indicating the
involvement of pineal, and also deep encephalic
photoreceptors

89. Diel rhythm of thermoregulation

90. EFFECT OF PINEALECTOMY ON SKELETON
DEVELOPMENT & COLOUR CHANGE
•Pinealectomy caused abnormality in the
formation of vertebral column in catfish/and also
other animals and resulted in marked reduction
in calcium and magnesium and total mineral
contents
•Pinealectomy also affects hibernation
•Pinealectomy also caused blanching in catfish -
due to contraction of chromatophores
Treatment with melatonin also caused blanching in
tadpoles (no effect in birds/mammals)

91. Role of pineal/day length in growth and
metabolism
Increase in day length results an increase in :
Plasma growth hormone
Insulin like growth factor
Thyroxine
High growth under increasing daylength can be
attributed to high food consumption and high pituitary
somototroph activity
Low growth under decreasing daylength may be
attributed to reduction in feed uptake
-Melatonin could also be involved in the process of
feeding and or digestion.
 Oral administration of melatonin has been shown to
reduce food intake

92. •Pineal effect on growth and digestibility
either may be mediated through an
influence on hypothalamo- hypophyseal axis
or by acting directly on the peripheral
endocrine glands
•Melatonin acts directly on the pituitary to
control GH and prolactin secretion
•At higher concentrations, melatonin
stimulates and at lower concentrations, it
inhibits GH release

94. Role of pineal in growth and metabolism
Experimental protocol
Pinealectomized and sham operated control
catfish were maintained at 25
o
C for 45 days and
fed on a diet containing about 40 percent protein
and exposed to the following light regimes
•LD 14:10
•LD 12:12
•LD 9:15
•DD
•LL

96. Conclusions on the role of pineal/day
length in growth and metabolism
•Increase in day length results an increase in :
Plasma growth hormone
Insulin like growth factor
Thyroxine
•High growth under increasing daylength can be
attributed to high food consumption and high pituitary
somototroph activity
•Low growth under decreasing daylength may be
attributed to reduction in feed uptake
•-Melatonin could also be involved in the process of
feeding and or digestion. Oral administration of
melatonin has been shown to reduce food intake

98. •Pineal effect on growth and digestibility
either may be mediated through an
influence on hypothalamo- hypophyseal
axis or by acting directly on the peripheral
endocrine glands
•Melatonin acts directly on the pituitary to
control GH and prolactin secretion
•At higher concentrations, melatonin
stimulates and at lower concentrations, it
inhibits GH release