PubMed Health⌕ Search

Biomedical subjects

L Brothers

Publications and source records attributed to L Brothers.

12 recordsLinked to original sources
PubMed1993

Mesial temporal neurons in the macaque monkey with responses selective for aspects of social stimuli.

Primates possess a sophisticated cognitive ability to interpret and respond to the social actions of conspecifics. Neurons in the temporal lobes of macaque monkeys which are selective for the appearance and motions of conspecifics have been described previously; the results reported here indicate that pathways which integrate such information converge in mesial temporal regions. Single neuron data from an alert macaque viewing moving pictures of other monkeys engaged in a variety of behaviors are presented. Neurons in medial nuclei of the amygdala and adjacent mesial temporal cortex are sensitive to identity, movement, and high-level aspects of depicted scenes.

Amygdala↗
PubMed1993

Durations of extended mental rehearsals are remarkably reproducible in higher level human performances.

It has been extremely difficult to quantify temporal aspects of higher level human brain function. We have found that mental rehearsals of musical performance of several minutes duration provide such a measure in that they can be highly reproducible, varying to less than 1%. These remarkable results pose fundamental neurophysiological problems. It is necessary to understand the underlying neuronal bases for this accuracy in the spatial-temporal activity of billions of neurons over minutes without sensory input. Further, they present a powerful constraint on neuronal models of brain function. Such highly reproducible (in duration) mental rehearsals might be used in conjunction with multielectrode EEG recordings to look for reproducible spatial-temporal patterns. Further, we suggest that our results may provide an extremely useful behavioural correlate for high level performance.

Electroencephalography↗
PubMed1990

Response of neurons in the macaque amygdala to complex social stimuli.

The presence of neurons in macaque temporal cortex and amygdala which fire selectively in response to social stimuli has been demonstrated by several investigators. The extent to which such neuronal populations may respond to a broad range of social features, including expressive movements and interactions, has not been fully explored due to the difficulty of presenting such complex stimuli in a controlled fashion. We describe a method for presenting moving segments of macaque behavior, visual and auditory, to animal subjects during single unit recording. The method permits a broad range of stimuli to be used both as probes and as controls. In addition, a novel technique for monitoring eye position in alert macaque subjects is described. We present results from the medial amygdala and adjacent cortex, demonstrating that neurons in these regions respond selectively to features of the social environment.

Amygdala↗
PubMed1989

Delayed intraperitoneal ureteric rupture following blunt abdominal trauma: case report.

Ureteric injury is uncommon and mostly follows penetrating trauma or surgical injury. Ureteric rupture following blunt abdominal trauma is rare, there being only a few reported cases. The case described here, in which blunt abdominal trauma resulted in delayed intraperitoneal rupture, appears to be the first report of this type of injury in blunt trauma.

Abdominal Injuries↗
PubMed1989

A biological perspective on empathy.

During the evolution of the primate CNS, organization of neural activity has been shaped by the need for rapid and accurate evaluation of the motivations of others. Using a broad biological approach, the author considers empathy from evolutionary, ontogenetic, and neurophysiological viewpoints. Emotional communication follows a developmental course in primate evolution and in individuals: specialized neural activity and CNS organization subserve the interpretation of social signals. Neurophysiological studies now in progress may shed light on fundamental questions about the nature of empathy.

Animals↗
PubMed1981

Sympathetic noradrenergic sprouting in response to central cholinergic denervation; a histochemical study of neuronal sprouting in the rat hippocampal formation.

An unusual example of neuronal sprouting occurs in the rat brain. Several weeks after fimbrial transection or septal lesions, peripheral sympathetic fibers appear in the dentate and hippocampal gyri. We compared the distribution of normal cholinergic septohippocampal fibers and nerve terminals with the distribution of noradrenergic sympathetic (sympathohippocampal) fibers after septal lesions using anterograde transport of horseradish peroxidase and fluorescence histochemistry. In addition, we destroyed other afferents to the hippocampal formation and examined the effect of subtotal septal lesions on acetylcholinesterase staining and the distribution of sympathohippocampal fibers. The combined results of these experiments suggest that peripheral noradrenergic fibers sprout specifically in response to destruction of central cholinergic fibers after septal lesions. This appears to be the first model of neuronal sprouting in the central nervous system where one identified transmitter system (noradrenergic) sprouts only in response to, and perhaps to replace, another specific transmitter system (cholinergic).

Acetylcholinesterase↗