Characterization of the kinetics and distribution of N-arachidonylethanolamine (anandamide) hydrolysis by rat brain.

Arachidonoylethanolamide or 'anandamide' is a naturally occurring derivative of arachidonic acid that has been shown to activate cannabinoid receptors in the brain. Its metabolic inactivation by brain tissue has been investigated. Anandamide is hydrolyzed by the membrane fraction of rat brain homogenate to arachidonic acid and ethanolamine.

Effects of intraocular mescaline and LSD on visual-evoked responses in the rat.

The effects of mescaline and LSD on the flash-evoked cortical potential (FEP) were determined in unrestrained rats with chronically-implanted electrodes. Systemic administration of mescaline or LSD significantly attenuated the primary component of the FEP at three stimulus intensities with the greatest effect observed 60-90 minutes following drug administration. The magnitude and specificity of the effects of these agents on the primary response suggest that they produce deficits in conduction through the retino-geniculato-cortical system.

Inhibition of heterosensory thalamocortical evoked potentials by delta-9-tetrahydrocannabinol.

The effects of delta-9-tetrahydrocannabinol on sensory activity in the thalamic intralaminar nuclei, centralis lateralis and the mesencephalic reticular formation were compared with the effects on cortical association or heterosensory systems in alpha-chloralose-anesthetized cats. The drug depressed the anterior marginal responses to multiple-modality sensory stimulation 30 min after administration of 2 mg/kg. Posterior suprasylvian responses were not significantly depressed except during 15 min postadministration.

The actions of THC on the intact hippocampus: a comparison of dentate and CA1 responses.

The effects of delta-9-tetrahydrocannabinol were compared on two afferent pathways of the rat hippocampal formation in urethane-anesthetized and chronically implanted awake animals. In urethane-anesthetized rats, THC produced a shift to the right in the input/output relationship without altering the relation between the measures of synaptic wave and the population spike of the CA1 response to contralateral CA3 stimulation. In contrast, the dentate response to perforant path stimulation was not altered by THC.

Separation of components of hippocampal field potentials by digital filtering on a PC-based microcomputer.

A versatile digital filtering system is described which enables separation of wave components of evoked potentials based on their frequencies. The utility of this technique is exemplified by application of digital filtering to hippocampal field potentials. Separation of population spikes from lower frequency synaptic potentials provides less ambiguous interpretation of the compound slope of the field potential during the first 5 milliseconds of the response.