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HISTOLOGICAL AND IMMUNOHISTOCHEMICAL STUDIES OF THE
BUCK'S PINEAL GLAND DURING LIGHT AND DARK PERIODS
Attia, H.F and Mazher, K
Department of Histology and Cytology, Faculty of Veterinary Medicine,
Benha and Beni‐Suef Universities
Corresponding author: Hossam Attia, Benha University. Egypt.P.O. 13736
Abstract: the present investigation was conducted on the pineal organs of 12 healthy bucks. Sixth
samples collected during dark period (at mid night) while the other six collected during light
period (at noon).The samples were processed and prepared for light and electron microscopic
examination. The pineal organ of bucks was surrounded by a thin fibrous capsule, the pia matter,
while the parenchyma was supported by extensive reticular network.The parenchyma of the
gland was formed of clusters or groups of pinealocytes intermingled with astroglia cells. Bundles
of unmyelinated nerve fibers were noticed in the organ. During dark period the pinealocytes
were large in size with finely granular cytoplasm containing well developed rER, mitochondria
and many secretory granules. Long branched cytoplasmic processes arised from the pinealocytes
to terminate near blood vessels or synapse with a nerve. The pinealocytes reacted positively with
antimelatonin antibodies. During the light period the pinealocytes appeared smaller in size with
clear non granular cytoplasm. The pinealocytes ahowed a very slight reaction to the
antimelatonin antibodies.
Keywords: buck, pineal gland, histology, immunostochemistry
INTRODUCTION
During the last few years, the study of the pineal gland (epiphysis cerebri) attracts the
attention of many authors at different aspects of biological sciences specially the histologists
and the physiologists.
Historically, the location of the pineal gland deep in the brain suggested to the philosophers
that it is a mystery gland with myth, superstition and metaphysical theories surrounding its
perceived function. Descartes (2002&2003) called it the seat of the soul. He believed that the
gland is the point of connection between the intellect and the body.
The pineal gland is occasionally associated with the sixth chakra (also called Ajna or third eye
chakra in yoga) or sometimes seventh chakra (crown). It is believed to be a dormant organ
that can be awakened to enable telepathic communications (Uz, et al , 2003).
Arendt and Skene (2005) discovered that melatonin, the most potent compound then known
to lighten frog skin, was present in highest concentration in the pineal body and its production
is stimulated by darkness and inhibited by light.
Histologically, the pineal gland of rat, pig, fish, bird, rabbit and hamster is thoroughly studied
by Ferreira‐Medeiros, et al (2007), Przyblyska‐Gornowicz and Lewczuk (1997), Hafeez (2005),
Ueck (1973), Romijn (1973) and matsushima, et al (1990) respectively while that of goat not
yet investigated.
Our study aimed to elucidate the light and electron microscopic pictures of pineal gland of the
buck beside the immunohistochemical localization of melatonin in the gland during dark and
light periods.
MATERIALS AND METHODS
Twelve healthy bucks aging 10‐12 months‐old were subjected to the present investigation. The
animals were subjected to a photoperiod of 12 hours dark and 12 hours light from rearing up
to the time of slaughtering. Six animals were sacrificed at midnight (at 12 O'clock) while the
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