Muscarinic M1, M3, Nicotinic,GABAA and GABAB Receptor ...

of the key contributors to motor deficits and cellular stress associated with
hypoglycemia in diabetes which is suggested to cause more damage at molecular
level than hyperglycemia. Dysfunction of cerebellar cholinergic receptors are
reported in hypoglycemia and hyperglycemia (Antony et al., 2010).
Brain stem
Brain stem reticular formation has been considered to play an important
role in generating behavioural states as well as in the modulation of pain sensation
(Pare & Steriade 1993). These reticular functions originate from interacting
neuronal groups in the brain stem, including cholinergic, adrenergic and
serotoninergic neurons (Steriade, 1996). Hypoglycemia result primarily from a
lowered glucose level in the brain and it adversely affects the central and
autonomic nervous systems (Charles et al., 2005). When glucose level was
lowered to 2.8 mmoles/L, the brain function was impaired in nondiabetic rats.
Symptoms of hypoglycemia result from the actions of hormones and
neurotransmitters in the process of restoring blood glucose levels. Severe
hypoglycemia triggers a cascade of events in vulnerable neurons that culminate in
cell death even after glucose normalization (Suh et al. 2003; 2005). Brainstem is
an important part of the brain in monitoring the glucose status and the regulation
of feeding (Guillod et al., 2003). Also, it serves as one of the key centres of the
central nervous system for regulating body homeostasis. Present study on
brainstem muscarinic receptors showed that the total muscarinic receptors
increased during hypoglycemic condition compared to diabetic and control.
Muscarinic M1 receptors are decreased and muscarinic M3 receptors are increased
during hypoglycemia. RT-PCR analysis also revealed a down regulation of the
muscarinic M1 receptor mRNA level during glucose deprivation in hypoglycemia.
This is in accordance with our receptor binding studies. Also, confocal studies
using specific antibodies of muscarinic M1 and M3 in brain stem confirmed the
Real time PCR analysis and binding assays. The adverse effects of mild
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