Neurophysiological effects of corticotropin-releasing factor in living slices of the olfactory area of the rat cortex.

Application of corticotropin-releasing factor (CRF) at concentrations of 10(-9) and 10(-8) M to living brain slices induced activation of the pre- and postsynaptic excitatory components of focal potentials recorded in the slices. The amplitudes and durations of the AMPA and NMDA components of EPSP increased during exposure to CRF, while the amplitude of the GABA(B)-mediated IPSP was suppressed. At the higher CRF concentration (10(-8) M), cells in slices showed epileptiform discharges. The effects of CRF were reversible and disappeared on washing. Long-term treatment with CRF (90 min) induced changes in cells in slices similar to those associated with long-term post-tetanic potentiation. These data provide evidence that CRF has marked activatory properties and influences the glutamatergic and GABAergic systems.