Caffeine exerts diverse actions in the body, including skeletal muscles, but a central stimulant effect may be the basis for its ergogenic effect (6). The study by Kalmar and Cafarelli (7) in this issue of the Journal of Applied Physiology investigates human neuromuscular fatigue and asks whether ingestion of caffeine alters voluntary activation, force, and the responses to femoral nerve and mo...

Caffeine exerts diverse actions in the body, including skeletal muscles, but a central stimulant effect may be the basis for its ergogenic effect (6). The study by Kalmar and Cafarelli (7) in this issue of the Journal of Applied Physiology investigates human neuromuscular fatigue and asks whether ingestion of caffeine alters voluntary activation, force, and the responses to femoral nerve and mo...

Caffeine exerts diverse actions in the body, including skeletal muscles, but a central stimulant effect may be the basis for its ergogenic effect (6). The study by Kalmar and Cafarelli (7) in this issue of the Journal of Applied Physiology investigates human neuromuscular fatigue and asks whether ingestion of caffeine alters voluntary activation, force, and the responses to femoral nerve and mo...

Nitric oxide (NO) is an unconventional membrane-permeable messenger molecule that has been shown to play various roles in the nervous system. How NO modulates ion channels to affect neuronal functions is not well understood. In gastropods, NO has been implicated in regulating the feeding motor program. The buccal motoneuron, B19, of the freshwater pond snail Helisoma trivolvis is active during ...

Hindlimb motoneuron excitability was compared among exercise-trained (E), sedentary (S), and spinal cord transected (T) Sprague-Dawley rats by examining the slope of the frequency-current (F/I) relationship with standard intracellular recording techniques in rats anesthetized with ketamine-xylazine. The T group included spinal transected and spinal isolated rats; the E animals were either spont...

Recruitment and repetitive firing of spinal motoneurons depend on the activation of persistent inward calcium and sodium currents (PICs) that are in turn facilitated by serotonin and norepinephrine that arise primarily from the brain stem. Considering that in rats motoneuron PICs are greatly facilitated by increasing the presynaptic release of norepinephrine with amphetamine, we sought similar ...

OBJECTIVE The authors asked the following research questions: will an anterior knee infusion model induce constant pain? will perceived pain alter motoneuron pool (MNP) excitability? and will treatments alter perceived pain and/or MNP excitability? METHODS Thirty-six neurologically healthy volunteers participated in this randomised controlled laboratory study. To induce anterior knee pain (AK...

The work described here focuses on novel patterns of motoneuron dendritic organization and dendritic development in relation to the recruitment patterns of spinal motoneurons that drive swimming in larval zebrafish. I first looked at the dendritic organization of motoneurons in freely swimming fish and tracked its emergence in relation to the maturation of locomotor behavior. I used transient e...

The well-documented role of neuromuscular activity as a regulator of motoneuron and muscle development raises important questions about the differentiation of excitability in motoneurons. We have recently described changes in expression of voltage-dependent calcium currents that take place during neuromuscular development in the chick embryo (McCobb et al., 1989). We now report similar analyses...