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

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Discussion
al., 1988). Low blood glucose levels are associated with negative mood states,
primarily self-reported ‘‘nervousness” (Boyle & Zrebiec, 2007). Moreover,
patients with a history of severe hypoglycemia showed significantly increased
levels of anxiety (Wredling et al., 1990) or ‘‘negative mood” (Gonder-Frederick et
al., 2008) relative to other patients with IDDM.
Inhibitory neurotransmission play an important role in the generation and
maintenance of certain seizure types in the corticothalamo - cortical circuits
(Engel, 1996). GABA-mediated neuronal synchronization initiates seizures in
some forebrain areas, mainly through the activation of GABAA receptors (Avoli et
al., 2005). Mechanisms like selective neuronal vulnerability, selective sensitivity
of neurotransmitters and the loss of autoregulation of cerebral blood flow are
suggested for neurological deficits followed by hypoglycemia (Lancet, 1985). The
consequence of hypoglycemic shock in diabetics is that the administration of
glucose did not result in immediate reversal of the neurological deficits (Wayne et
al., 1990).
It is evident from the present study that neurological dysfunction follows
the hypofunction of GABA receptors and thereby impaired GABAergic
transmission in the cortical regions. Decreased GABA neurotransmission in the
present model of hypoglycemia is also suggested to lead to anxiety disorders
associated with glucose deprivation.
Cerebellum
GABA is a predominant neurotransmitter, which is synaptically released,
mediates fast inhibitory synaptic transmission and regulates excitatory activity of
neurons (Martin & Tobin, 2000; Olsen & Avoli, 1997). The Aα1 subunit is the
most dominant a subunit in all types of mature cerebellar neurons, and appears
when and where GABAergic synapses are formed (Merlo et al., 2007; Takayama
& Inoue, 2003). Cerebellum is a region of the brain that plays an important role in
the integration of sensory perception, memory consolidation, coordination and