Expression of catechol-O-methyltransferase in the brain and periphery of normal and MPTP-treated common marmosets.

Catechol-O-methyltransferase (COMT) inhibition is widely used to potentiate the effects of levodopa in Parkinson's disease but the effects of nigral dopaminergic cell loss and levodopa treatment on COMT activity are not known. The present study investigated the expression of COMT in the brain and liver of normal common marmosets, and animals treated with MPTP and those treated with levodopa to induce dyskinesia. Reverse transcript PCR demonstrated the expression of COMT mRNA in the liver, cortex and striatum of normal marmosets.

Ionic currents underlying the response of rat dorsal vagal neurones to hypoglycaemia and chemical anoxia.

A proportion of dorsal vagal neurones (DVN) are glucosensors. These cells respond to brief hypoglycaemia either with a K(ATP) channel-mediated hyperpolarization or with depolarization owing to an as yet unknown mechanism. K(ATP) currents are observed not only during hypoglycaemia, but also in response to mitochondrial inhibition.

Neuronal responses to transient hypoglycaemia in the dorsal vagal complex of the rat brainstem.

Several regions of the mammalian brain contain glucosensing neurones. In vivo studies have suggested that those located in the hypothalamus and lower brainstem are involved in glucoprivic feeding and homeostatic control of blood glucose. We have identified and characterized hypoglycaemia-sensitive neurones in the dorsal vagal complex of the brainstem using in situ hybridization, single-cell RT-PCR and whole-cell patch-clamp recordings from rat brainstem slices.