Related Experiment Video
Updated: Aug 7, 2026

Multi-unit Recording Methods to Characterize Neural Activity in the Locust (Schistocerca Americana) Olfactory Circuits
Published on: January 25, 2013
Evidence for central chemoreception in the midline raphé
D G Bernard1, A Li, E E Nattie
1Department of Physiology, Dartmouth Medical School, Lebanon, New Hampshire 03756-0001, USA.
Abstract:
We injected acetazolamide (AZ; 5 x 10(-6) M; 1 nl; n = 14), its inactive analogue 2-acetylamino-1,3,4-thiadiazole-5-sulfon-t-butylamide (5 x 10(-5) M; n = 6), or mock cerebrospinal fluid (n = 5) into the caudal raphé in the midline brain stem of anesthetized paralyzed ventilated rats. These AZ injections have been shown to produce a focal region of tissue acidosis with a radius < 350 microns and are used as a probe for sites of central chemosensitivity. Compared with control injections, AZ injection into the raphé, as demonstrated by anatomic analysis of injection location, significantly increased the amplitude of the integrated phrenic neurogram over 10-40 min. Not all raphé injections produced such a response. AZ injections identified as responders (n = 8 of 14) increased integrated phrenic amplitude 43.3 +/- 10.7% (SE) of baseline 20 min after the injection. We conclude that the midline caudal raphé contains sites of ventilatory chemoreception.
More Related Videos
10:42A Lateralized Odor Learning Model in Neonatal Rats for Dissecting Neural Circuitry Underpinning Memory Formation
Published on: August 18, 2014
06:32Hybridization Chain Reaction RNA Whole-Mount Fluorescence In situ Hybridization of Chemosensory Genes in Mosquito Olfactory Appendages
Published on: November 17, 2023
Related Concept Videos
Olfaction
The olfactory receptors are embedded in the cilia of the...
Functional Brain Systems: Reticular Formation
Within the reticular formation, there are several distinct nuclei that can be classified into three broad categories. The Raphe nuclei are located along the midline of the brainstem. They are primarily known for their role in synthesizing and releasing serotonin, a neurotransmitter involved in regulating mood, appetite, sleep, and circadian rhythms. The...
Physiology of Smell and Olfactory Pathway
The olfactory...
Neural Control of Respiration
Respiratory Centers in the Brainstem
Two primary areas comprise the respiratory center: the medullary respiratory center in the medulla oblongata and the pontine respiratory group in the pons. The...
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Physiology of Respiration II: Neurogenic Control of Respiration
Central Control
The brainstem is the primary site of central control, hosting respiratory centers: