James A. Waschek

Learn More
MRC Brain Metabolism Unit (A.J.H) Royal Edinburgh Hospital, Edinburgh, Scotland; US-Japan Biomedical Research Laboratories (A.A.), Tulane University Medical Center, Belle Chasse, Louisiana; Department of Clinical Biochemistry (I.G.), Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel; CNRS UPR 9023 (L.J.), CCIPE, F-34094 Montpellier,(More)
The mammalian suprachiasmatic nucleus (SCN) is a master circadian pacemaker. It is not known which SCN neurons are autonomous pacemakers or how they synchronize their daily firing rhythms to coordinate circadian behavior. Vasoactive intestinal polypeptide (VIP) and the VIP receptor VPAC2 (encoded by the gene Vipr2) may mediate rhythms in individual SCN(More)
Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are members of a superfamily of structurally related peptide hormones that includes glucagon, glucagon-like peptides, secretin, gastric inhibitory peptide (GIP) and growth hormone-releasing hormone (GHRH). VIP and PACAP exert their actions through three GPCRs(More)
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(More)
Pituitary adenylyl cyclase activating peptide (PACAP) is widely expressed in the embryonic brain at the onset of neurogenesis, and is strongly upregulated in several models of nerve injury. Moreover, high-affinity PACAP receptors are expressed in proliferative zones in the embryonic and postnatal nervous system suggesting that PACAP regulates the(More)
Peripheral nerve injury models are used to investigate processes that can potentially be exploited in CNS injury. A consistent change that occurs in injured peripheral neurons is an induction in expression of pituitary adenylyl cyclase activating peptide (PACAP), a neuropeptide with putative neuroprotective and neuritogenic actions. PACAP-deficient mice(More)
Previous studies indicate that light information reaches the suprachiasmatic nucleus through a subpopulation of retinal ganglion cells that contain both glutamate and pituitary adenylyl cyclase-activating peptide (PACAP). Although the role of glutamate in this pathway has been well studied, the involvement of PACAP and its receptors is only beginning to be(More)
Corticosteroids are the mainstay treatment for most severe inflammatory disorders. Due to the considerable toxicity associated with their long-term use, there is a great need for alternative treatments. Recently, two closely related neuropeptides with potent neuromodulatory activities, vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase(More)
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(More)
It is widely accepted that most suprachiasmatic nucleus (SCN) neurons express the neurotransmitter GABA and are likely to use this neurotransmitter to regulate excitability within the SCN. To evaluate the possibility that inhibitory synaptic transmission varies with a circadian rhythm within the mouse SCN, we used whole cell patch-clamp recording in an(More)