Hyperexcitable reflex blinks are a cardinal sign of Parkinson's disease. The first step in the circuit linking the basal ganglia and brainstem reflex blink circuits is the inhibitory nigrostriatal pathway (Basso et al., 1996). The current study reports the circuits linking the superior colliculus (SC) to trigeminal reflex blink circuits. Microstimulation of the deep layers of the SC suppresses ...

The effect of some endogenous components -endogenous opiates, cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP) and somatostatin-as inhibitory or excitatory transmitters in the local nervous pathways involved in peristaltic responses was examined. The peristaltic reflex was studied using a modification of the Trendelenberg preparation. In each preparation, the luminal distens...

There are only few reports on the trigemino-cervical reflex in humans and there is debate over the best method of reflex examination. The aim of this study was, comparing different methods, to provide a reproducible method for evaluating the trigemino-cervical reflex. The trigemino-cervical reflex was studied in 32 healthy volunteers. The stimulation was applied to the supraorbital, infraorbita...

The Hoffmann reflex and the Achilles tendon reflex were measured in a group of 194 subjects suspected of having a lumbosacral root compression syndrome. The Achilles tendon reflex was elicited manually with a metal hammer. There was a high correlation between the H-M interval and the Achilles tendon reflex-M interval. The usefulness of the Achilles tendon reflex was evaluated in a selected sub-...

Skilled interactions with new environments require flexible changes to the transformation from somatosensory signals to motor outputs. Transcortical reflex gains are known to be modulated according to task and environmental dynamics, but the mechanism of this modulation remains unclear. We examined reflex organization in the sensorimotor cortex. Subjects performed point-to-point arm movements i...

Objectives: To investigate the modulation of the soleus H reflex in spinal cord injured (SCI) subjects resulting from imposed changes in hip angle and to establish whether changes in H reflex amplitude co-vary with changes in reflex latency and duration. Methods: H reflexes were recorded using conventional methods in 7 SCI subjects in the supine position. The right leg was secured by a leg brac...

Abstract A subthreshold pulse of transcranial magnetic stimulation (TMS) on the motor cortex can modulate amplitude monosynaptic reflex (H-reflex) elicited in flexor carpi radialis (FCR) muscle, a method known as TMS-conditioning H-reflex. The purpose this study was to establish intersession reliability over course three sessions. Eleven healthy participants received either peripheral nerve (PN...

It is known that somatosensory reflex during voluntary arm movement is modulated anticipatorily according to given tasks or environments. However, when and how reflex amplitude is set remains controversial. Is the reflex modulation completed preparatorily before movement execution or does it vary with the movement? Is the reflex amplitude coded in a temporal manner or in a spatial (or state-dep...