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

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Discussion
shows impaired expression thereby function, during hypoglycemia which
contributes to hypoglycemia associated functional deficit.
Hippocampus
The hippocampus is highly enriched in cholinergic terminals which
originate from the medial septal pathways, and this system has a profound effect
on hippocampal neuron functionality and reports demonstrated that the most
abundant muscarinic receptor in the hippocampus is that of the musacrinic M1
subtype (Krnjevic, 1993; Levey, 1995). Excitatory modulations by muscarinic
cholinergic receptors in hippocampal neurons have been well recognized. The
high density of the muscarinic M1 receptor protein in this region of the CA1
subfield (Levey, 1995) supports the likely involvement of this subtype as a
participant in the cholinergic modulation of protein synthesis and excitatory
neuronal modulations. Diabetes mellitus and its most common treatment side
effect, hypoglycemia, have multiple effects on the central nervous system.
Prolonged or profound hypoglycemia leads to coma, seizures and potentially
permanent brain damage (McCall, 2004).
Because of the numerous modulatory effects exerted through
phosphoinositide- linked muscarinic receptors in the hippocampus, we evaluated
how the muscarinic receptors respond to hypoglycemic stress. Significant
alterations in binding parameters and gene expression in total muscarinic,
muscarinic M1, M3 receptors were observed following hypoglycemia in diabetic
and control rats. We observed a transient decreases in the mRNA levels of
muscarinic receptor subtypes following recurrent episode of hypoglycemia.
Immunohistochemistry study of muscarinic M1, M3 receptors in the hippocampus
of control and experimental rats using confocal microscope confirmed a similar
expression pattern which confirmed at protein level. Neurons react to the decrease
in oxygen and glucose by initiating a series of adaptive responses to mitigate
excitotoxicity. Both long term mechanisms involving alterations in gene