TY - JOUR
T1 - Developmental Switch in Neuropeptide Y and Melanocortin Effects in the Paraventricular Nucleus of the Hypothalamus
AU - Melnick, Igor
AU - Pronchuk, Nina
AU - Cowley, Michael A.
AU - Grove, Kevin L.
AU - Colmers, William F.
N1 - Funding Information:
Supported by Canadian Institutes of Health Research grants MT10250 and OHN 63278 to W.F.C. and NIH R01-DK060685 and RR00163 (ONPRC) to K.L.G. W.F.C. is a Medical Scientist of the Alberta Heritage Foundation for Medical Research. All physiological experiments were performed at the University of Alberta. We would like to thank Dr J. Meier for his helpful advice on the immunocytochemistry of GABAergic synapses and Dr. J. Tasker for his comments on an earlier version of the manuscript.
PY - 2007/12/20
Y1 - 2007/12/20
N2 - Homeostatic regulation of energy balance in rodents changes dramatically during the first 3 postnatal weeks. Neuropeptide Y (NPY) and melanocortin neurons in the arcuate nucleus, a primary energy homeostatic center in adults, do not fully innervate the paraventricular nucleus (PVN) until the third postnatal week. We have identified two classes of PVN neurons responsive to these neuropeptides, tonically firing neurosecretory (NS) and burst-firing preautonomic (PA) cells. In neonates, NPY could inhibit GABAergic inputs to nearly all NS and PA neurons, while melanocortin regulation was minimal. However, there was a dramatic, age-dependent decrease in NPY responses specifically in the PA neurons, and a 3-fold increase in melanocortin responses in NS cells. These age-dependent changes were accompanied by changes in spontaneous GABAergic currents onto these neurons. This primarily NPYergic regulation in the neonates likely promotes the positive energy balance necessary for growth, while the developmental switch correlates with maturation of homeostatic regulation of energy balance.
AB - Homeostatic regulation of energy balance in rodents changes dramatically during the first 3 postnatal weeks. Neuropeptide Y (NPY) and melanocortin neurons in the arcuate nucleus, a primary energy homeostatic center in adults, do not fully innervate the paraventricular nucleus (PVN) until the third postnatal week. We have identified two classes of PVN neurons responsive to these neuropeptides, tonically firing neurosecretory (NS) and burst-firing preautonomic (PA) cells. In neonates, NPY could inhibit GABAergic inputs to nearly all NS and PA neurons, while melanocortin regulation was minimal. However, there was a dramatic, age-dependent decrease in NPY responses specifically in the PA neurons, and a 3-fold increase in melanocortin responses in NS cells. These age-dependent changes were accompanied by changes in spontaneous GABAergic currents onto these neurons. This primarily NPYergic regulation in the neonates likely promotes the positive energy balance necessary for growth, while the developmental switch correlates with maturation of homeostatic regulation of energy balance.
UR - http://www.scopus.com/inward/record.url?scp=37049000596&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=37049000596&partnerID=8YFLogxK
U2 - 10.1016/j.neuron.2007.10.034
DO - 10.1016/j.neuron.2007.10.034
M3 - Article
C2 - 18093530
AN - SCOPUS:37049000596
SN - 0896-6273
VL - 56
SP - 1103
EP - 1115
JO - Neuron
JF - Neuron
IS - 6
ER -