Herpes simplex virus type 1 (HSV1) was injected into either the aortic depressor nerve or the vagus nerve in the rabbit. Four or 5 days after injection of virus, the rabbit brain was processed immunohistochemically to demonstrate viral antigen. After injection into the aortic nerve HSV1 positive cells were found principally ipsilaterally within the nucleus tractus solitarius, area postrema, caudal and rostral ventrolateral medulla oblongata, the spinal trigeminal complex, raphe nuclei, A5 area, locus coeruleus, parabrachial nucleus, periaqueductal gray, ventrolateral hypothalamic area, paraventricular nucleus, amygdala, bed nucleus of the stria terminalis and insular cortex. Double labeling studies indicated that approximately 85% of the virus-containing neurons in the ventrolateral medulla, and virtually all the HSV-positive neurons in the A5 area and locus coeruleus also contained tyrosine hydroxylase. In the raphe nuclei and parapyramidal region approximately 33% of virus-containing cells reacted positively with PH8 antibody, a marker for serotonin synthesis. After injection of HSV1 into the vagus nerve labeled cells were found in similar brain areas, with a more bilateral distribution. The HSV - positive neurons may be involved in the processing of baroreceptor-derived information.
- Blood pressure
- Cardiovascular regulation
- Nucleus tractus solitarius
- Ventrolateral medulla oblongata