Biomedical subjects

R A Sugerman

Publications and source records attributed to R A Sugerman.

3 recordsLinked to original sources

PubMed1998

Soleus H-reflex to S1 nerve root stimulation.

H-reflexes in normals were elicited by percutaneous electrical and magnetic stimulation of proximal nerve roots at the cauda equina. H-M interval to S1 nerve root stimulation at the level of the S1 foramen was 6.8 +/- 0.33 ms, with side to side difference of 0.16 +/- 0.13 ms. Compression/ischemia of the sciatic nerve in the mid-thigh abolished the H-reflex to stimulation of the tibial nerve at the popliteal fossa when the H-reflex to S1 nerve root stimulation was preserved. The length of the S1 nerve root in human cadavers was measured to be 17.5 +/- 03 cm, providing an estimated dorsal root conduction velocity of 67.3 m/s and a ventral root conduction velocity of 54 m/s. We conclude that the H-M interval to S1 root stimulation can provide reliable measures of conduction within the spinal canal including proximal afferents, anterior horn cells and ventral roots.

Adult↗

PubMed1988

Feeding evoked by electrical stimulation in collared lizards.

Feeding was evoked in collared lizards, Crotaphytus collaris, using electrical stimulation of the brain (ESB). Stimulation sites were tested in the forebrain and midbrain of 39 animals. Six stimulation loci were localized in the septal, preoptic, hypothalamic, and thalamic areas from which ESB feeding was evoked. Feeding could be elicited by ESB over several test days, but the number of feeding bouts per test session was usually low. However, several animals ate or approached food consistently when stimulated.

Animals↗

PubMed1978

Agonistic behavior elicited by electrical stimulation of the brain in western collared lizards, Crotaphytus collaris.

Western collared lizards, Crotaphytus collaris, were tested in three experiments using electrical stimulation of the brain. In experiment 1, agonistic behavior (defensive, aggressive and escape) responses were elicited in free-moving unanesthetized lizards. In experiment 2, areas were localized from which gular extension, a common component of defensive and aggressive behavior, could be evoked in anesthetized animals. Experiment 3 was carried out to demonstrate that defensive and aggressive behavior could be elicited from the same stimulation sites both in anesthetized and unanesthetized lizards. Initially, gular extension was evoked while the animal was anesthetized and later the animal was tested while freely moving and unanesthetized. Based on a combined plot of the sites from which defensive and aggressive behavior was evoked in experiments 1--3, the higher threshold sites (51--750 muA) were in the dorsal ventricular ridge anterior, amygdaloid complex, septal and preoptic areas, hypothalamus, thalamus and adjacent to the nucleus profundus mesencephali (NPM) and reticular formation. Lower threshold sites (up to 50 muA) are found in the NPM and the reticular formation. Escape behavior can be evoked from stimulation sites within or adjacent to areas from which defensive and aggressive behavior can be elicited.

Aggression↗