Responses of Brainstem Respiratory Neurons to Activation of Midbrain Periaqueductal Gray in the Rat
Eupneic breathing has been shown to be affected by output from the midbrain periaqueductal gray matter (PAG) (Huang et al. 2000; Hayward et al. 2003; Subramanian et al. 2007). In the rat, anatomical tracing studies have demonstrated connections between the PAG and other brainstem areas. It is generally accepted that PAG efferents activate descending pathways that originate in the medulla (Holstege 1991b). The aims of our studies were to isolate and record from respiratory cells in the ventral respiratory group (VRG) and the nucleus tractus solitarius (NTS) regions of the rat brainstem and to examine the changes in firing patterns and timing of these cells following excitatory amino acid (EAA) stimulation of the PAG. We also investigated the effect of β-adrenergic blockade in the vlNTS on the PAG induced respiratory patterning.
KeywordsExcitatory Amino Acid Nucleus Tractus Solitarius Respiratory Neuron Ventral Respiratory Group Dorsal Brainstem
Unable to display preview. Download preview PDF.
- Feldman, J.L. (1986) Neurophysiology of breathing in mammals. In: Handbook of Physiology. The Nervous System. Intrinsic Regulatory System in the Brain. Washington, DC: Am. Physiol. Soc. 4, 463–524.Google Scholar
- Holstege, G. (1991b) Descending pathways from the periaqueductal gray and adjacent areas. In: A. Depaulis and R. Bandler (Eds.), The Midbrain Periaqueductal Gray Matter: Functional Anatomical and Immunohistochemical Organization. Plenum Press, New York, pp. 239–265.Google Scholar
- Paxinos, G. and Watson, C. (1997) The rat brain in stereotaxic co-ordinates. San Diego, CA: Academic respiratory groups of neurons in the medulla of the rat. Brain Res. 419, 87–96.Google Scholar