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

associated with spatial and working memory tasks (Gioiosa et al., 2008).
Neurobehavioral alterations that manifest as deficits in locomotor responses are
related to nicotinic receptors (Eriksson et al., 2000) and deficits in spatial learning
and memory (Eppolito & Smith, 2006). Behavioural deficit suggests impairment
in their ability to integrate sensory input with appropriate motor commands to
balance their posture and at the same time adjust their limb movements on the grid
and is indicative of cerebellar dysfunction (Krishnakumar et al., 2009). Spatial
learning, which often involves training on a particular maze, has been shown to
rely heavily on the septohippocampal pathway. Cholinergic neurons in the
septohippocampal pathway are intermingled with GABAergic neurons, and
damage to both cholinergic and GABAergic septohippocampal pathways
contribute to spatial memory deficits (Pang et al., 2001).
The grid walk test in experimental rats demonstrated the impairment of
the motor function and coordination in the hypoglycemic rats compared to diabetic
and control rats. Increased number of foot slips in grid walk test suggests
impairment in their ability to integrate sensory input with appropriate motor
commands to balance their posture. Motor skills and motor learning abilities are
dependent on the integrity of the central cholinergic system (Thouvarecq et al.,
2001). Diabetes mellitus has been reported to be accompanied by a number of
behavioural and hormonal abnormalities, including reduced locomotor activity
(Marshall et al., 1976). Cholinergic system, particularly that of the neostriatum
and of the septohippocampal formation, plays a role in locomotion and motor
skills (Monmaur et al., 1997) particularly in learning of motor abilities
(Shapovalova, 1998). Previous reports showed impaired performance in
hypoglycemic rats in rotarod test (Joseph et al., 2010).
Thus behavioral test conducted in experimental rats showed that
hypoglycemia results in impaired motor and cognitive function thus leading to
deficiency in exploratory activity and spatial memory related tasks which is
attributed to impaired cholinergic and GABAergic neurotransmission.
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