Neurons expressing VIP/PHI precursor mRNA have been localized in the interstitial nucleus of Cajal. Unilateral surgical cut through the medial forebrain bundle failed to influence VIP/PHI mRNA expression in the Cajal nucleus while brainstem hemisection or unilateral transection of the medial longitudinal fascicle reduced it markedly, ipsilateral to the knife cuts. Thus, in contrast to forebrain projecting VIP neurons in the rostral periaqueductal gray, VIP/PHI neurons in the Cajal nucleus project downwards, to the lower brainstem.

Download full-text PDF

Source

Publication Analysis

Top Keywords

vip/phi neurons
8
interstitial nucleus
8
nucleus cajal
8
cajal nucleus
8
projections vip/phi
4
neurons
4
neurons interstitial
4
nucleus
4
cajal
4
cajal rat
4

Similar Publications

Degeneration of corpus callosum appears in patients with amyotrophic lateral sclerosis (ALS) before clinical signs of upper motor neuron death. Considering the ALS-associated impairment of astrocytic glutamate uptake, we have characterized the expression and activity of the glutamate transporter isoforms GLT-1a and GLT-1b in the corpus callosum of transgenic rats expressing a mutated form of the human superoxide dismutase 1 (hSOD1(G93A)). We have also studied the effect of peptide histidine isoleucine (PHI), a vasoactive intestinal peptide (VIP)/pituitary adenylate cyclase-activating polypeptide (PACAP) receptor 2 (VPAC(2)) agonist on glutamate transporters both in vivo and in callosal astrocytes.

View Article and Find Full Text PDF

The effects of pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal peptide (VIP), peptide histidine-isoleucine (PHI) and peptide histidine-methionine (PHM) on cyclic AMP formation were studied in parallel on rat cerebral cortical slices, primary neuronal cultures and primary glial (astrocyte) cultures. PACAPappeared to be the most potent agent in all biological systems. The rank order of the peptides' potency was as follows: PACAP > VIP > PHI = PHM for cortical slices and neuronal cell cultures, and PACAP >> PHM approximately VIP > PHI for glial cell cultures.

View Article and Find Full Text PDF

Neurons expressing VIP/PHI precursor mRNA have been localized in the interstitial nucleus of Cajal. Unilateral surgical cut through the medial forebrain bundle failed to influence VIP/PHI mRNA expression in the Cajal nucleus while brainstem hemisection or unilateral transection of the medial longitudinal fascicle reduced it markedly, ipsilateral to the knife cuts. Thus, in contrast to forebrain projecting VIP neurons in the rostral periaqueductal gray, VIP/PHI neurons in the Cajal nucleus project downwards, to the lower brainstem.

View Article and Find Full Text PDF

Vasoactive intestinal polypeptide (VIP), acting via the VPAC(2) receptor, is a key signaling pathway in the suprachiasmatic nuclei (SCN), the master clock controlling daily rhythms in mammals. Most mice lacking functional VPAC(2) receptors are unable to sustain behavioral rhythms and lack detectable SCN electrical rhythms in vitro. Adult mice that do not produce VIP (VIP/PHI(-/-)) exhibit less severe alterations in wheel-running rhythms, but the effects of this deficiency on the amplitude, phasing, or periodicity of their SCN cellular rhythms are unknown.

View Article and Find Full Text PDF

Disrupted circadian rhythms in VIP- and PHI-deficient mice.

Am J Physiol Regul Integr Comp Physiol

November 2003

Mental Retardation Res. Ctr., Univ. of California - Los Angeles, 760 Westwood Plaza, Los Angeles, CA 90024-1759, USA.

The related neuropeptides vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI) are expressed at high levels in the neurons of the suprachiasmatic nucleus (SCN), but their function in the regulation of circadian rhythms is unknown. To study the role of these peptides on the circadian system in vivo, a new mouse model was developed in which both VIP and PHI genes were disrupted by homologous recombination. In a light-dark cycle, these mice exhibited diurnal rhythms in activity which were largely indistinguishable from wild-type controls.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!