Hippocampus depolarization mediation

Ohno-Shosaku, Tsubokawa, et al. (2002) demonstrated that not only DSI but also DSE can be induced in the rat and mouse hippocampus. DSE in the hippocampus was mediated by the presynaphc CBj receptor and endocannabinoids released from depolarized postsynaphc neurons. They compared DSE and DSI in slices from the same animals and found that DSE was much less... 

H2 receptor stimulation in mammalian cerebral cortex and hippocampus produces excitation by inhibition of Ca2+-activated K+ conductances (Table 14-2). This effect resembles that produced by activation of [3-adrenergic receptors in these areas and both are mediated by increases in the cAMP-PKA pathway [1], H2 receptor activation also facilitates depolarization by enhancing the IH current,... 

Physiological studies have identified both post- and presynaptic roles for ionotropic kainate receptors. Kainate receptors contribute to excitatory post-synaptic currents in many regions of the CNS including hippocampus, cortex, spinal cord and retina. In some cases, postsynaptic kainate receptors are codistributed with AMPA and NMDA receptors, but there are also synapses where transmission is mediated exclusively by postsynaptic kainate receptors for example, in the retina at connections made by cones onto off bipolar cells. Extrasynaptically located postsynaptic kainate receptors are most likely activated by spill-over glutamate (Eder et al. 2003). Modulation of transmitter release by presynaptic kainate receptors can occur at both excitatory and inhibitory synapses. The depolarization of nerve terminals by current flow through ionotropic kainate receptors appears sufficient to account for most examples of presynaptic regulation however, a number of studies have provided evidence for metabotropic effects on transmitter release that can be initiated by activation of kainate receptors. The hyperexcitability evoked by locally applied kainate, which is quite effectively reduced by endocannabinoids, is probably mediated preferentially via an activation of postsynaptic kainate receptors (Marsicano et al. 2003). 

HT4 Receptor-Mediated Depolarization of CA1 Pyramidal Cells Activation of 5-HT4 receptors depolarizes pyramidal cells of the CA1 region of the hippocampus (45,46) through a mechanism that involves cAMP but is... 

Hampson RE, Zhuang SY, Weiner JL, Deadwyler SA (2003) Functional significance of cannabinoid-mediated, depolarization-induced suppression of inhibition (DSI) in the hippocampus. J Neurophysiol 90 55-64... 

Martin, L.A., Wei, D. S., and Alger, B.E. (2001) Heterogeneous susceptibility of GABA(A) receptor-mediated IPSCs to depolarization-induced suppression of inhibition in rat hippocampus, J. Physiol., 532(Pt. 3), 685-700. 

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