For the first time, an in-depth study has been made of the distribution of fibers and cell bodies containing calcitonin gene-related peptide (CGRP) in the minipig brainstem using an indirect immunoperoxidase technique. The animals studied were not treated with colchicine. Cell bodies containing CGRP were found in 20 nuclei/regions of the brainstem. These perikarya were located in somatomotor, b...

Studies have shown that following opiate withdrawal, the spontaneous discharge rate of locus coeruleus (LC) neurons remarkably increases. Combination of intrinsic mechanisms with extrinsic excitatory modulations mediates the withdrawal-induced hyperactivity of LC neurons. The nucleus paragigantocellularis (PGi) provides the main excitatory inputs to LC and plays a pivotal role in opiate withdra...

We have theorized that large neurons in the ventral and medial reticular formation of the medulla are critical for both autonomic and cortical arousal. To test this theory, we anesthetized rats with urethane, lowered concentric bipolar stimulating electrodes into the medullary reticular formation, and implanted electroencephalogram (EEG) and ECG recording electrodes. We stimulated in the medull...

The midbrain nucleus mesencephalicus lateralis pars dorsalis (MLd) is thought to be the avian homologue of the central nucleus of the mammalian inferior colliculus. As such, it is a major relay in the ascending auditory pathway of all birds and in songbirds mediates the auditory feedback necessary for the learning and maintenance of song. To clarify the organization of MLd, we applied three cal...

Effects of anticonvulsants were determined on thalamic afterdischarge in gallamine-immobilized cats and d-tubocurarine-immobilized rats in order to clarify the participation of anticonvulsants in the thalamus. Thalamic afterdischarge was induced by electrical stimulation of cat nucleus centralis lateralis and rat nucleus reticularis at 50 Hz, 1 msec for 4 sec. In cats, diphenylhydantoin, carbam...

Afferent connections of the two main areas in the telencephalon, the visual wulst and the ectostriatum, were traced in the zebra finch by injection of horseradish peroxidase and staining with tetramethylbenzidine (TMB). Nuclei projecting to the hyperstriatum accessorium (HA) or the HIS region (lamina hyperstriatica intercalatus superior) were: (1) ipsilaterally the n. dorsalis anterior pars lat...

A descending inhibitory mechanism from the periaqueductal gray (PAG) to the spinal cord through the nucleus raphe magnus (NRM) is strongly involved in endogenous analgesic system produced by acupuncture stimulation. In addition to the PAG to NRM system which descends in the medial pathway of the brain stem, the nucleus reticularis lateralis (NRL) situated in the lateral part of the brain stem i...

To observe the effect of electroacupuncture (EA) on nucleus ventralis posterior lateralis (VPL) thalami activated by visceral noxious stimulation and to explore the impact of EA on the mechanism of acupoint sensitization under a pathological state of the viscera, EA was applied at bilateral "Zusanli-Shangjuxu" acupoints. The discharge of VPL neurons was response to EA increased after colorectal...