Aquaculture America 2020

February 9 - 12, 2020

Honolulu, Hawaii

DISTRIBUTION OF GAMMA-AMINOBUTYRIC ACID (GABA) IN THE CENTRAL NERVOUS SYSTEM OF THE MALE MUD CRAB Scylla olvacea

Kanjana Khornchatri* , Jirawat Saetan, Tipsuda Thongbuakaew , Sirirak Mukem , Thanapong Kruangkum ,  and Prasert Sobhon.
 
Chulabhorn Int ernational College of Medicine, Thammasat University,
Pathumthani 12121, Thailand
kanjan5325@gmail.com
 

Mud crab,  Scylla olivacea is one of the most important economic  value  marine species in Thailand. Recently, its population is rapidly decreasing, thus the understanding of neurotrans mitters/ neurohormones/ neuromodulators controlling of reproduction may help to improve the productivity in aquaculture. Many studies have reported the mechanisms of  several  neurotransmitters or neurohormones  that involved in  the repro duction of decapod crustaceans, especially serotonin, octopamine, and dopamine. They were detected throughout the central nervous system (CNS) of  decapod crustaceans, which control the reproduction  via regulating various neuropeptides . γ-aminobutyric acid (GABA) has implicated in the modulation of numerous physiological functions, including reproduction in many vertebrate species . However, the existence of GABA in the mud crab,  Scylla olivacea remains unclear . We aim to investigate the distribution of GABA throughout the CNS by whole-mount immunofluorescence technique . The result revealed a ubiquitous distribution of  GABA immunoreactivity (-ir )  throughout the CNS. In  the brain, GABA-ir was detected  in  the neuronal clusters 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17 , and fibers, including  olfactory neuropil (ON) , circumesophageal connective (CEC) ,  and  antenna II neuropil (AnN) .  In  the ventral nerve cord, GABA-ir  was  broadly  found in subesophageal ganglion (SEG), thoracic ganglion (TG), and abdominal ganglion (AG). GABA-ir was detected in the small- and medium-sized neurons in the SEG .  In  the TG, GABA-ir  was  also presented in  the large-sized neurons between thoracic neuropils (TN)  and fiber around  the thoracic artery (TA) .  Moreover, GABA-ir  was  found in  the medium- and large-sized neurons in the AG . Therefore, the  existence and distribution of  GABA  in the male mud crab,  Scylla olivacea may suggest that GABA  may play a role in the controlling of reproduction via stimulating neuropeptides release in the CNS.