THE ROSTRAL PORTION OF THE VENTRAL MEDULLA OR RVM COMPRISES SEVERAL GROUPS OF NEURONS THAT ARE THOUGHT TO BE INVOLVED IN CARDIO-RESPIRATORY CONTROL, including the retrotrapezoid nucleus (RTN), portions of the nucleus paragigantocellularis lateralis (PGCL), the parapyramidal region, and the caudal raphé.1 The RVM has anatomic connections to the dorsal and ventral respiratory groups,2 the interme...

The organization of neurons and fibers in the cochlear nuclei of the alligator lizard (Gerrhonotus multicarinatus) was examined with light and electron microscopy. In this species, much is known about the anatomy and physiology of the inner ear including the cochlear nerve, but little is known about the synaptic connections of cochlear fibers on second-order neurons. These data will help to dev...

Differences in arrival time and intensity (or level) of sound between the ears serve as cues for localization of sound in many animals. Barn owls use interaural time difference (ITD) and interaural level difference (ILD) for localization in azimuth and elevation, respectively. The owl's brain processes these two cues in separate pathways. The nucleus laminaris is the first site that detects ITD...

Larval lampreys respond to skin illumination with a delayed burst of swimming in an attempt to escape the light. The photoresponse, which is independent of the lateral eyes and pineal organs, is most readily elicited by light shone on the tail. Behavioral studies in larval lampreys demonstrate that photosensory afferents innervating the tail are carried by a trunk lateral line nerve supplying r...

In this study the effect of adenosine and caffeine on spontaneous activity of paragigantocellularis (PGi) neurons was investigated. The spontaneous activity of PGi neurons was significantly decreased by microinjection of adenosine (10 nM, 0.5 µl) into PGi nucleus of both control and morphine-dependent rats. The decrease in firing rate of PGi neurons of morphine-dependent rats was greater than t...

The distribution of neurons and fibres containing monoamines (MA, that is noradrenaline, dopamine, and serotonin) was studied in the brain of the weakly electric fish, Eigenmannia lineata, by formaldehyde-induced fluorescence histochemistry. Control experiments using a catecholamine-precursor (Dopa), a MA-depleting (reserpine), and a MA-accumulating (nialamide) drug, together with microspectrof...

1. The distribution of labeled macromolecules was studied within the dorsolateral thalamic nuclei of the pigeon after unilateral intraocular injection of either aH-proline, 3H-leucine or aH-fueose. The highest densities of grains were found in nucleus dorsolateralis anterior, pars lateralis at its dorsolateral aspect (DLLd) and in nucleus lateralis anterior (LA) whereas moderate labeling was ob...

-A neuropharmacological stud) WBS undertaken in the cat to obtain further evidence of the role ofacetylcholine in vestibular function. It was shown that the vestibular nerve contains about half or less the enzymatic activity of choline acetyltransferase. acetylcholinesterase. cholinesterase and total cholinesterase than nucleus vestlbularls later&s (NVL). Field potentials as well as discharge o...

The spinal and peripheral innervation of the clitoris and vagina are fairly well understood. However, little is known regarding supraspinal control of these pelvic structures. The multisynaptic tracer pseudorabies virus (PRV) was used to map the brain neurons that innervate the clitoris and vagina. To delineate forebrain input on PRV-labeled cells, the anterograde tracer biotinylated dextran am...

The supraspinal regulation of genital reflexes is poorly understood. The brainstem nucleus paragigantocellularis (nPGi) of rats is a well-established source of tonic inhibition of genital reflexes. However, the organization, gonadal steroid receptor expression, and activity of nPGi afferents during sex have not been fully characterized in male and female rats. To delineate the anatomical and ph...