Despite extensive study during the last 10 years, several aspects of the neural control of prolactin secretion are still unelucidated. In mammals, the most important feature of this control is the existence of a predominant inhibitory regulation, as demonstrated by a number of older experiments involving hypothalamo-hypophyseal deconnexion, interruption of the portal circulation, ectopic grafts...

Receptors for peptide hormones and neurotransmitters are integral components of the plasma membrane of cells which serve to couple the external milieu to the intracellular regulators of metabolism. These macromolecules are usually high molecular weight glycoproteins, and in many cases appear to have more than one subunit capable of binding the hormone. The interaction of the hormone or neurotra...

aMonoaminergic projections from brainstem to cortex via the ascending reticular activating system are illustrated here. Perhaps one form of arousal is a stimulated type of external vigilance, with tense hyperarousal, putting the individual on the lookout for threats from the environment. This type of arousal may be mediated by the monoamines dopamine, norepinephrine, serotonin, and acetylcholin...

The hypothalamus receives neuronal afferents from numerous sources including inputs from limbic structures, such as the amygdala and hippocampus, and from brainstem regions involved in the regulation of the cardiovascular system and other autonomic functions. These afferents using a vast array of neurotransmitters and neuropeptides influence the activity of the hypothalamic neurons which synthe...

Four biogenic amines: octopamine, tyramine, dopamine and serotonin act in C. elegans to modulate behavior in response to changing environmental cues. These neurotransmitters act at both neurons and muscles to affect egg laying, pharyngeal pumping, locomotion and learning. A variety of experimental approaches including genetic, imaging, biochemical and pharmacological analyses have been used to ...

Amino acid concentrations were measured in CSF samples obtained by lumbar puncture in 51 patients, cervical puncture in 16 patients, spinal drains in nine patients, ventricular taps in five patients and from below a spinal block in six patients. There was evidence of a rostrocaudal gradient for GABA and taurine and a reverse gradient for alanine and asparagine. Lumbar CSF glycine concentrations...