Biomaterial Database

Convergence of noxious and non-noxious cutaneous afferents and baroreceptor afferents onto single adrenal sympathetic neurons in anesthetized rats. 1984

K Ito, and A Sato, and K Shimamura, and R S Swenson

Single units of the adrenal sympathetic nerve (n = 46) were dissected and characterized with respect to tonic discharge and response to cutaneous and baroreceptor stimulation. The frequency of tonic discharge averaged 1.6 Hz and cardiovascular rhythmic modulation was observed in 53% of the units. The stimuli employed in the present study included phenylephrine-induced increases in blood pressure and pinching or brushing of lower chest skin. Mean unit activity increased 27% on lower chest pinching stimulation, decreased 12% on lower chest brushing stimulation and decreased 62% on phenylephrine-induced baroreceptor stimulation. Although there was a tendency for units with higher tonic firing frequency to have a greater response to stimulation, this relationship was not significant for pinching or brushing of lower chest skin. The close correlation between tonic activity and response to phenylephrine was explicable on the basis of a near total depression of many units, which resulted in a larger decrease in firing frequency for units with initially high spontaneous discharge rates. As might be expected, units with cardiovascular rhythmicity manifested greater responses to baroreceptor activation. This correlation was independent of tonic rate of discharge since rhythmic and non-rhythmic units did not significantly differ in tonic activity. While a majority of units responded in a typical fashion to all three stimuli (i.e. with increases to pinching and decreases to brushing and phenylephrine administration), there was little correlation between the response magnitude of individual units to any two of the stimuli employed. We conclude, therefore, that most adrenal sympathetic units receive convergent reflex input from cutaneous noxious and non-noxious afferents as well as from baroreceptor afferents, although for any individual unit the quantitative significance of each input varies.

UI	MeSH Term	Description	Entries
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D009619	Nociceptors	Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.	Pain Receptors,Receptors, Pain,Nociceptive Neurons,Neuron, Nociceptive,Neurons, Nociceptive,Nociceptive Neuron,Nociceptor,Pain Receptor
D010656	Phenylephrine	An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.	(R)-3-Hydroxy-alpha-((methylamino)methyl)benzenemethanol,Metaoxedrin,Metasympatol,Mezaton,Neo-Synephrine,Neosynephrine,Phenylephrine Hydrochloride,Phenylephrine Tannate,Neo Synephrine,Tannate, Phenylephrine
D011311	Pressoreceptors	Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.	Baroreceptors,Receptors, Stretch, Arterial,Receptors, Stretch, Vascular,Stretch Receptors, Arterial,Stretch Receptors, Vascular,Arterial Stretch Receptor,Arterial Stretch Receptors,Baroreceptor,Pressoreceptor,Receptor, Arterial Stretch,Receptor, Vascular Stretch,Receptors, Arterial Stretch,Receptors, Vascular Stretch,Stretch Receptor, Arterial,Stretch Receptor, Vascular,Vascular Stretch Receptor,Vascular Stretch Receptors
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D001794	Blood Pressure	PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.	Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D000313	Adrenal Medulla	The inner portion of the adrenal gland. Derived from ECTODERM, adrenal medulla consists mainly of CHROMAFFIN CELLS that produces and stores a number of NEUROTRANSMITTERS, mainly adrenaline (EPINEPHRINE) and NOREPINEPHRINE. The activity of the adrenal medulla is regulated by the SYMPATHETIC NERVOUS SYSTEM.	Adrenal Medullas,Medulla, Adrenal,Medullas, Adrenal
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001339	Autonomic Fibers, Preganglionic	NERVE FIBERS which project from the central nervous system to AUTONOMIC GANGLIA. In the sympathetic division most preganglionic fibers originate with neurons in the intermediolateral column of the SPINAL CORD, exit via ventral roots from upper thoracic through lower lumbar segments, and project to the paravertebral ganglia; there they either terminate in SYNAPSES or continue through the SPLANCHNIC NERVES to the prevertebral ganglia. In the parasympathetic division the fibers originate in neurons of the BRAIN STEM and sacral spinal cord. In both divisions the principal transmitter is ACETYLCHOLINE but peptide cotransmitters may also be released.	Autonomic Fiber, Preganglionic,Fiber, Preganglionic Autonomic,Fibers, Preganglionic Autonomic,Preganglionic Autonomic Fiber,Preganglionic Autonomic Fibers
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.