The cellular mechanisms of habituation and dishabituation of the gill-withdrawal reflex in Aplysia were studied with an isolated abdominal ganglion connected to a piece of skin from the tactile receptive field of the reflex. By obtaining simultaneous intracellular recordings from both the sensory neurons and one of the main identified motor neurons, we have been able to reduce the reflex to its...

The root cause of the most common and serious of the sleep disorders is impairment of breathing, and a number of factors predispose a particular individual to hypoventilation during sleep. In turn, obstructive hypopneas and apneas are the most common of the sleep-related respiratory problems and are caused by dysfunction of the upper airway as a conduit for airflow. The overarching principle th...

We have used the technique of spatial facilitation to examine the interactions between the signals conveyed by the corticospinal tract and those of cutaneous afferents in the hindlimb of the intact, walking cat. Microstimulation was applied to 20 cortical sites in the hindlimb representation of the motor cortex and to three different cutaneous nerves innervating the hindpaw in four cats. Condit...

The trigeminal reflex blink is an ideal system to investigate whether stimulus paradigms that produce long-term potentiation (LTP) in vitro modify motor learning in humans. Presentation of 12 trains of low-intensity, high-frequency stimuli (HFS) to the supraorbital branch of the trigeminal nerve (SO) modified subsequent reflex blinks of human subjects. When HFS occurred concurrently with reflex...

The relative contributions of intramuscular and extramuscular receptors to changes in the reflex excitability of soleus motoneurons, following muscle stretch, have been studied in man. It was found that reflex excitability was decreased by muscle stretch. The extent of the decrease was related to the amount of stretch, irrespective of whether the latter was produced by dorsiflexion of the ankle...

Aiming to develop a new, non invasive approach to spinal cord neuromodulation , we assessed the possibility modulating the spinal cord function by transcutaneous direct current stimulation. In a group of 12 healthy volunteers we evaluated the after-effects of anodal and cathodal tsDCS delivered on the skin overlying the thoracic spinal cord on somatosensory potentials (SEPs) evoked in normal su...

Dorsal root-evoked stimulation of sensory afferents in the hemisected in vitro rat spinal cord produces reflex output, recorded on the ventral roots. Transient spinal 5-HT2C receptor activation induces a long-lasting facilitation of these reflexes (LLFR) by largely unknown mechanisms (Machacek et al., 2001). Two Sprague-Dawley substrains were used to characterize network properties involved in ...

Autonomic dysregulation in patients suffering from major depression is expressed in cardiovascular regulation as well as in the pupillary light reflex. We used spectral analysis and unrest indices to uncover indications of autonomic imbalance in resting pupillographic recordings. Significantly increased unrest and mean pupil diameters were observed in depressed patients. Pupillometric parameter...

the term reflex epilepsy in reserved for a small subgroup o seizures that occur regularly in response to specific stimuli. our patient is a 20- year old male, who had pleasure, euphoria, loss of conciousness and generalized tonic- clonic convulstion when he watched tv since ten years. during puberty the patient that self-induced reflex epilepsy with photic stimulation, when watching tv or looki...