Faculty Collaboration Database

Substance P and enkephalinergic synapses onto neurokinin-1 receptor-immunoreactive neurons in the pre-Bötzinger complex of rats. Eur J Neurosci 2004 Jan;19(1):65-75

Date

01/31/2004

Pubmed ID

14750964

DOI

10.1111/j.1460-9568.2004.03099.x

Scopus ID

2-s2.0-1642540065 (requires institutional sign-in at Scopus site)   30 Citations

Abstract

Our previous studies have demonstrated that neurokinin-1 receptor (NK1R)-immunoreactive (ir) neurons in the pre-Bötzinger Complex (pre-BötC), the hypothesized kernel of respiratory rhythmogenesis, receive both glutamatergic excitatory and GABAergic or glycinergic inhibitory inputs. Neuromodulators, such as substance P (SP) and opioids, play important roles in normal respiratory activity and respiratory disorders. The identification of the relationship between neurotransmitters and NK1R-ir neurons at the cellular level is essential for understanding the synaptic interaction within the pre-BötC network. Using immunofluorescence and immunogold-silver staining, we wished to exploit SP and enkephalin (ENK) immunoreactivity and their relationships with glutamate, GABA, glycine, or NK1R in the pre-BötC in adult Sprague-Dawley rats. The pre-BötC contained a substantial amount of SP-ir and ENK-ir boutons. They were largely colocalized with glutamate and much less so with GABA. Glycine immunoreactivity was rarely found in either SP-ir or ENK-ir boutons. A number of SP-ir boutons were ENK-ir as well. Synapses were commonly found between SP-ir or ENK-ir terminals and NK1R-ir neurons in the pre-BötC. Most of them were asymmetric. Symmetric synapses made up 10% of all synapses examined between SP-ir boutons and NK1R-ir neurons, and 19% of ENK/NK1R synapses. Colocalization of SP and/or ENK with glutamate in boutons in the pre-BötC implies the combined synaptic release of excitatory amino acid and neuropeptides, which may exert combined post-synaptic effects onto NK1R-ir neurons and contribute to respiratory activity.

Author List

Liu YY, Wong-Riley MT, Liu JP, Wei XY, Jia Y, Liu HL, Fujiyama F, Ju G

MESH terms used to index this publication - Major topics in bold

Animals
Enkephalins
Fluorescent Antibody Technique
Glutamic Acid
Glycine
Immunohistochemistry
Male
Medulla Oblongata
Microscopy, Electron
Neural Inhibition
Neural Pathways
Presynaptic Terminals
Rats
Rats, Sprague-Dawley
Receptors, Neurokinin-1
Respiratory Center
Respiratory Physiological Phenomena
Substance P
Synaptic Transmission
gamma-Aminobutyric Acid