Analysis of spontaneous activity patterns of human thalamic ventrolateral neurons and their modifications due to functional brain changes.

In the human thalamic ventralis lateralis nucleus the spontaneous activity of 235 single units during 38 stereotactic operations in locally anaesthetized parkinsonian patients was analysed. Two basic cell types (A and B) were shown to exist in this nucleus: (i) with unitary irregular (2-40/s) discharges characterized by a tendency to spike grouping in the range of 4-6 Hz and 10-30 Hz (A-type, 74%), (ii) with bursting discharges firing in short trains (5-30 ms) characterized by an unstable rhythmic 3-6 Hz pattern similar to a low-threshold Ca2+ intrinsic burst structure of discharges (B-type, 26%). The functional brain changes after a motor tests performance were accompanied by the appearance of two different transient modifications of activity of A-cells pattern into rhythmic burst discharges: (i) in the range of 3-6 Hz, similar to the bursts found for B-cells and recorded mainly in the anterior ventrolateral region in rigid patients, (ii) in the range of 5 +/- 1 Hz, characterized by other interspike interval and recorded in the posterior ventrolateral region in patients with tremor.

Exogenous gaseous superoxide potentiates the antinociceptive effect of opioid analgesic agents.

The study examined the potentiation of the antinociceptive action of opioid analgesics produced by gaseous superoxide (GS) in the rat hind paw withdrawal test (PWT) and by GS or hydrogen peroxide (HP) in the formalin test. In the PWT, inhalation of GS for 50 minutes before i.p.

The neurotropic activity of a structural analog of ACTH(5-7).

The tripeptide glutamyl-arginyl-proline (ERP) mimicking some structural features of the N-terminal fragment of adrenocorticotropic hormone, ACTH(5-7), has been synthesized. In contrast with ACTH fragments, ERP (0.015-0.