%0 Journal Article
%T Effects of prostaglandin E2 on the electrical properties of thermally classified neurons in the ventromedial preoptic area of the rat hypothalamus
%A Heather J Ranels
%A John D Griffin
%J BMC Neuroscience
%D 2005
%I BioMed Central
%R 10.1186/1471-2202-6-14
%X To characterize the electrical properties of VMPO neurons, whole-cell recordings were made in tissue slices from male Sprague-Dawley rats. Our results indicate that PGE2 dependent firing rate responses were not the result of changes in resting membrane potential, action potential amplitude and duration, or local synaptic input. However, PGE2 reduced the input resistance of all VMPO neurons, while increasing the excitability of temperature insensitive neurons and decreasing the excitability of warm sensitive neurons. In addition, the majority of temperature insensitive neurons responded to PGE2 with an increase in the rate of rise of the depolarizing prepotential that precedes each action potential. This response to PGE2 was reversed for warm sensitive neurons, in which the prepotential rate of rise decreased.We would therefore suggest that PGE2 is having an effect on the ionic currents that regulate firing rate by controlling how fast membrane potential rises to threshold during the prepotential phase of the action potential.Fever, an elevation in body temperature, is thought to play an adaptive role in the immune system's ability to fight infection [1]. A suggested mechanism for its production and maintenance is a shifting of the thermostatic set-point into the hyperthermic range [1,2]. Through the integration of both central and afferent thermal information, this set-point is established by the activity of neurons in the preoptic and anterior regions of the hypothalamus (PO/AH) that can be thermally classified on the basis of their inherent ability to respond to changes in temperature [3]. The majority of PO/AH neurons are considered temperature insensitive, showing little or no temperature dependent changes in firing rate. Approximately 30% of PO/AH neurons can be classified as warm sensitive, responding to local warming with an increase in firing rate [4]. While there has been considerable debate as to the criteria that should be used to classify a neuron as war
%U http://www.biomedcentral.com/1471-2202/6/14