Reciprocal connections between the claustrum and the auditory cortical fields in the cat. An experimental study using light- and electron microscopic anterograde degeneration methods, and the horseradish peroxidase retrograde axonal transport.

The reciprocal connections between the claustrum and the auditory cortical fields AI, AII and Ep were investigated by means of Nauta and Fink-Heimer selective silver impregnation procedures, electron microscopic identification of degenerated axons and synaptic boutons, and with the Mesulam horseradish peroxidase retrograde tracing technique. The course and termination of degenerating corticoclaustral axons were investigated following circumscript lesions of the AI, AII and Ep areas in 19 cats. The greatest amount of degeneration debris was observed following destruction of the AII area.

Electrophysiological effects of propranolol and carbachol locally injected into nucleus raphe dorsalis in cats.

The effect of propranolol and carbachol injected directly into nucleus raphe dorsalis (RD) on the evoked potentials, their recovery cycles and on the spontaneous EEG activity recorded in the RD and the visual and somatosensory cortical regions was investigated. It was found that the changes in these electrophysiological parameters induced by propranolol and carbachol were similar and showed an increase in the excitability level in both the RD and the neocortex, mainly in the somatosensory cortex. The activating effect of carbachol was much more pronounced as compared with that of propranolol.

Effect of a new GABA-ergic substance gabalid on brain bioelectric activity of cat.

The effect of the GABA-ergic substance gabalid on the bioelectric activity of cats was studied using electrodes introduced into substantia nigra (SN), nucleus caudatus (NC), Amygdala basolateralis ( Abl ), mesencephalic reticular formation (MRF) and sensor motor cortex (Sm). Gabalid was administered i.p.

Influence of morphine and haloperidol on the bioelectrical activity of n. raphe, n. caudatus, s. nigra and the visual cortex of cats.

The changes in the bioelectrical activity of n. raphe dorsalis (RD), s. nigra (SN), n.

Modified Nauta and Fink-Heimer procedures with special reference to the demonstration of monoaminergic pathways in the central nervous system.

Modifications of the selective silver impregnation methods of Nauta and Fink-Heimer are described. Both procedures were tested in wide variety of species: from reptiles to carnivores, as well as in human autoptic cases. The modified Nauta procedure is recommended as a method of choice for tracing axonal trajectories due to an improved impregnation selectivity of the degenerating axoplasm.