The inferior colliculus (IC) is highly modulated by descending projections from higher auditory and nonauditory centers. Traditionally, corticofugal fibers were believed to project mainly to the extralemniscal IC regions. However, there is some anatomical evidence suggesting that a substantial number of fibers from the primary auditory cortex (A1) project into the IC central nucleus (ICC) and a...

Interactions of peripheral inputs to the motoneuron of the kitten fetus as young as 3 weeks prenatal were studied by reflex discharge from the ventral root as well as by recording from single motoneurons. Facilitation was found between two synergists in fetuses I to 2 weeks before birth. Intracellular recording showed that the facilitation could be explained by summation of excitatory postsynap...

A sizeable number of spinothalamic tract axons terminate in the posterior thalamus. The functional roles and precise areas of termination of these axons have been a subject of recent controversy. The goals of this study were to identify spinothalamic tract neurons (STT) within the cervical enlargement that project to this area, characterize their responses to mechanical and thermal stimulation ...

Rheumatoid arthritis (RA) and rat models of RA exhibit symmetrical mirror-image spread. Many studies have sought to understand the underlying mechanisms and have reported contralateral effects that are manifested in many different forms. It is now well accepted that neurogenic mechanisms contribute to the symmetrical spread of inflammation. However, very few investigators have directly assessed...

The role of the substantia innominata (SI) in the generation of a behavior mediated by the prefrontal (PF) cortex was examined in two Japanese monkeys. PF neuronal activities related to a visual tracking task by wrist movement were recorded and neural responses to SI stimulation were analyzed. Sixty-six neurons showed task-related activity and were classified into 3 types. Type 1 (n = 31) showe...

Interactions of peripheral inputs to the motoneuron of the kitten fetus as young as 3 weeks prenatal were studied by reflex discharge from the ventral root as well as by recording from single motoneurons. Facilitation was found between two synergists in fetuses I to 2 weeks before birth. Intracellular recording showed that the facilitation could be explained by summation of excitatory postsynap...

Goldfish hypothalamic neuroendocrine cells have been investigated with intracellular recordings. The cells showed resting potentials of 50 mv and action potentials up to 117 mv followed by a long lasting and prominent diphasic hyperpolarizing afterpotential. The action potential occurred in two steps indicating sequential invasion. "Total" neuron (input) resistance was measured to be 3.3 x 10(7...

The main axons of mammalian sensory neurons are usually viewed as passive transmitters of sensory information. However, the spindle afferents of jaw-closing muscles behave as if action potential traffic along their central axons is phasically regulated during rhythmic jaw movements. In this paper, we used brainstem slices containing the cell bodies, stem axons, and central axons of these sensor...

The properties of dorsal root ganglion (DRG) neurons have been mostly investigated in culture of dissociated cells, and it is uncertain whether these cells maintain the electrophysiological properties of the intact DRG neurons. Few attempts have been made to record from DRG neurons in the intact ganglion using the patch clamp technique. In this study, rat DRGs were dissected and incubated for a...

The thalamic input was assessed from the amplitude of field evoked potential induced antidromically in the lemniscus medialis by ventrobasal complex stimulation. In the control rats, the amplitude of the antidromic response was greater during waking with theta activity in the dorsal hippocampus, i.e., in the attentive and/or psychomotor active animal, than during waking without theta rhythm. Du...