Effect of stimulation of the brain-stem reticular formation on cerebral blood flow and oxygen consumption

AbstractDynamic exercise elicits fluctuations in blood pressure (BP) and cerebral blood flow (CBF). This study investigated responses in BP and CBF during cycling exercise and post-exercise hypotension (PEH) using positron emission tomography (PET). CBF was measured using oxygen-15-labeled water (H2 15O) and PET in 11 human subjects at rest (Rest), at the onset of exercise (Ex1), later in the exercise (Ex2), and during PEH. Global CBF significantly increased by 13% at Ex1 compared with Rest, but was unchanged at Ex2 and during PEH. Compared with at Rest, regional CBF (rCBF) increased at Ex1 (20~42%) in the cerebellar vermis, sensorimotor cortex for the bilateral legs (M1Leg and S1Leg), insular cortex and brain stem, but increased at Ex2 (28~31%) only in the vermis and M1Leg and S1Leg. During PEH, rCBF decreased compared with Rest (8~13%) in the cerebellum, temporal gyrus, piriform lobe, thalamus and pons. The areas showing correlations between rCBF and mean BP during exercise and PEH were consistent with the central autonomic network, including the brain stem, cerebellum, and hypothalamus (R2=0.25–0.64). The present study suggests that higher brain regions are coordinated through reflex centers in the brain stem in order to regulate the cardiovascular response to exercise.

Download Full-text

Positive dorsal root potentials evoked by stimulation of the brain stem reticular formation

Brain Research ◽

10.1016/0006-8993(73)90051-6 ◽

1973 ◽

Vol 54 ◽

pp. 305-308 ◽

Cited By ~ 5

Author(s):

Michael P. Owen ◽

Charles J. Hodge

Keyword(s):

Brain Stem ◽

Reticular Formation ◽

Dorsal Root ◽

Dorsal Root Potentials ◽

The Brain ◽

Stimulation Of

Download Full-text

Blocking interactions between brain-stem reflex facilitation and sympathetic reflex enhancement

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.3.669 ◽

1959 ◽

Vol 196 (3) ◽

pp. 669-673 ◽

Cited By ~ 3

Author(s):

H. B. Kelly ◽

L. M. N. Bach

Keyword(s):

Brain Stem ◽

Reticular Formation ◽

Quadriceps Muscle ◽

Chemical Interference ◽

Simultaneous Stimulation ◽

Splanchnic Nerves ◽

Peripheral Locus ◽

The Brain ◽

Brain Stem Reflex ◽

Stimulation Of

In cats anesthetized with Nembutal the integrity of the lumbar sympathetic chain is necessary for the maintenance of the normal basal height of the patellar reflex. The centrally activated sympathetic component of brain stem enhancement of the patellar reflex is consistently and totally abolished by either surgical or chemical interference with the sympathetic supply to the hind leg. Although the use of sympatholytic drugs does not affect (presumably) synaptic facilitation of reflex activity resulting from brain stem reticular stimulation, mechanical stimulation of either the lumbar sympathetic or splanchnic nerves will cause a temporary but marked depression of this facilitation. Simultaneous stimulation of either the lumbar sympathetic or splanchnic nerves completely and consistently blocks the facilitatory effects of brain stem reticular stimulation. Conversely, simultaneous stimulation of the brain stem reticular formation consistently and totally blocks the enchancement of the patellar reflex which results from stimulation of the peripheral lumbar sympathetic or splanchnic nerves. The former phenomenon does not result from any peripheral locus of interaction between adrenaline and the innervation of the quadriceps muscle. Cross perfusion experiments indicate that the locus of interaction may involve the brain stem reticular formation.

Download Full-text

Increase in ICP Produced by Electrical Stimulation of the Brain Stem Reticular Formation in Cats with Spinalization and Vagotomy

Intracranial Pressure VII ◽

10.1007/978-3-642-73987-3_80 ◽

1989 ◽

pp. 292-294

Author(s):

M. Maeda ◽

S. Matsuura

Keyword(s):

Electrical Stimulation ◽

Brain Stem ◽

Reticular Formation ◽

The Brain ◽

Stimulation Of

Download Full-text

Brain stem reticular influences on lumbar axial muscle activity. I. Effective sites

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1984.246.3.r389 ◽

1984 ◽

Vol 246 (3) ◽

pp. R389-R395 ◽

Cited By ~ 3

Author(s):

P. A. Femano ◽

S. Schwartz-Giblin ◽

D. W. Pfaff

Keyword(s):

Brain Stem ◽

Reticular Formation ◽

Electromyographic Activity ◽

Axial Muscle ◽

Axial Musculature ◽

Excitatory Responses ◽

Ipsilateral Stimulation ◽

The Brain ◽

Muscle Responses ◽

Stimulation Of

Lumbar axial muscle responses to electrical stimulation of the brain stem reticular formation were used to characterize reticular influences on these muscles. Electromyographic recordings were obtained from the transversospinalis, medial longissimus, and lateral longissimus systems in the urethan-anesthetized rat. Ipsilateral stimulation of the pontomedullary reticular formation evoked excitatory responses in these muscles. Trains of pulses were required, but currents as low as 15 microA were effective. Contralateral reticular stimulation with currents similar to those that elicited activation during ipsilateral stimulation at the same brain stem levels could inhibit lumbar electromyographic activity. The results suggest that the motoneurons innervating the lumbar axial musculature in the rat receive strong reticulospinal influences that could be important for postural maintenance and the expression of certain behaviors.

Download Full-text