Showing papers in "International Journal of Neuroscience in 1972"
TL;DR: With few exceptions, units dorsolateral to the MSO were excited by ipsilateral sounds, and units ventromedial to theMSO, or in the ventral nucleus of the lateral lemniscus (VNLL), were exciting by contralateral sounds.
Abstract: The locations of various categories of units are described and correlations are found between unit properties and unit locations. Units on the edges of the medial superior olive (MSO) and the lateral superior olive (LSO) appear to have properties different from units inside these nuclei. Many units in the dorsomedial periolivary nucleus had wide tuning curves and some had very long latencies. Almost all units in the medial nucleus of the trapezoid body (MNTB) had irregular firing patterns, but most units in the LSO and the dorsolateral periolivary nucleus had regular firing patterns. Class 2 (off) units may correspond to ‘stellate’ cells of the MNTB.With few exceptions, units dorsolateral to the MSO were excited by ipsilateral sounds, and units ventromedial to the MSO, or in the ventral nucleus of the lateral lemniscus (VNLL), were excited by contralateral sounds.Best frequencies were arranged from high to low (1) from ventromedial to dorsolateral in the MSO, (2) from the medial limb to the lateral limb i...
471 citations
TL;DR: In this article, the authors examined response properties to sounds in single auditory units in the superior olivary complex and the ventral nucleus of the lateral lemniscus and divided them into ten classes, four classes were defined by single properties (spike waveshape or the timing of responses to sound bursts) and the remaining six classes were defining by which ear excited or inhibited the units.
Abstract: Response properties to sounds were examined in single auditory units in the superior olivary complex and the ventral nucleus of the lateral lemniscus. Units were divided into ten ‘classes’; four classes were defined by single properties (spike waveshape or the timing of responses to sound bursts) and the remaining six classes were defined by which ear excited or inhibited the units. Units were also divided according to the types of poststimulus-time histograms they produced in response to sound bursts, and they were separately divided according to the shape of their inter-spike interval histograms. These latter two groupings were highly correlated with each other and with unit class, and were combined into a single classification scheme called ‘firing-pattern type’.Units were divided into six groups based on the shapes of their tuning curves; data on the bandwidths of tuning curves are also presented. Data are presented on spontaneous firing rate, thresholds to best-frequency tones, and latency of respons...
344 citations
TL;DR: Spontaneous discharges of single units in the eighth cranial nerve of anesthetized cats were recorded with micropipets and studied by means of interspike-interval histograms.
Abstract: Spontaneous discharges of single units in the eighth cranial nerve of anesthetized cats were recorded with micropipets and studied by means of interspike-interval histograms. The histograms for units in the auditory branch generally have modes less than 10 msec, high skew and high coefficients of variation (CV). The histograms for units in the superior division of the vestibular branch generally have modes longer than 10 msec but have either low skew and low CV, low skew and high CV, or high skew and low CV. Units with high and low skews are found in almost equal numbers in the anterior portion of the superior division, whereas an overwhelming proportion of the units in the posterior portion have low skew.
104 citations
TL;DR: This paper presents some thoughts on functional organization in cerebral tissue and various models are discussed which have been suggested to describe the pseudorandom behavior of brain cells, leading to a view of the brain as an information processor and its role in learning, memory, remembering and forgetting.
Abstract: This paper presents some thoughts on functional organization in cerebral tissue. 'Spontaneous' wave and unit firing are considered as essential phenomena in the handling of information. Various models are discussed which have been suggested to describe the pseudorandom behavior of brain cells, leading to a view of the brain as an information processor and its role in learning, memory, remembering and forgetting.
64 citations
TL;DR: Some biochemical, morphological and pharmacological characteristics of the fast migrating as well as the slow moving proteins will be considered using the retino-tectal pathway of the pigeon as a model.
Abstract: This presentation is concerned with the proteins supplied by the neuronal cell body to the axon and particularly the nerve terminals. Some biochemical, morphological and pharmacological characteris...
52 citations
TL;DR: In this paper, the question is posed as to whether the behavior of living matter gives us any reason to reconsider fundamental physical principles, i.e., whether the problems of neuronal activity are too complex to confront directly with physical principles.
Abstract: The question is posed as to whether the behavior of living matter gives us any reason to reconsider fundamental physical principles. How is the problem of language likely to influence our concepts of physics? The problems of neuronal activity are felt to be too complex to confront directly with physical principles. We need to understand the physical basis of all symbolic activity on a more fundamental level.
52 citations
TL;DR: The problem of memory and learning is discussed on the basis of a concise review of present knowledge and some physico-chemical aspects of a molecular memory system are discussed and a biopolyelectrolytic model system is described.
Abstract: The problem of memory and learning is discussed on the basis of a concise review of our present knowledge in this intriguing field of behavioral research. The results of a great variety of biochemical and biophysical studies support the current comprehension that biological information storage has a chemical molecular basis. Before a biosynthetic consolidation of phenotypic memory takes, however, place, there must be a physical interaction between the electric impulses of the neuronal network with an already existing molecular matrix. A mechanism proposed for fast imprint with low energy expenditure comprises conformational metastability (in certain cases leading to hysteretic phenomena) and conformational changes in macromolecules and macromolecular organizations such as membranes. Some physico-chemical aspects of a molecular memory system are discussed and a biopolyelectrolytic model system is described.
46 citations
TL;DR: Microchromatography of dansylated substances was used to estimate the serotonin content of a giant serotonin-containing neuron situated in the metacerebral ganglia of Helix pomatia, and perfusion of the central nervous system of this snail with 14C-5-HTP showed that the giant serotonin -containing neuron can use this precursor to form 14 C-serotonin, whereas a non-amine containing cell can not.
Abstract: Microchromatography of dansylated substances was used to estimate the serotonin content of a giant serotonin-containing neuron situated in the metacerebral ganglia of Helix pomatia. Perfusion of the central nervous system of this snail with 14C-5-HTP showed that the giant serotonin-containing neuron can use this precursor to form 14C-serotonin, whereas a non-amine containing cell can not. The significance of these results is discussed.
41 citations
TL;DR: A general statistical description of learning processes is given, using an extension of classical information theory which is able to characterize a system's subjective uncertainty about a set of data and the relevance associated with them.
Abstract: A general statistical description of learning processes is given, using an extension of classical information theory which is able to characterize a system's subjective uncertainty (subjective entropy) about a set of data and the relevance associated with them. Learning is defined as a process in which the system's subjective entropy or, equivalently, its missing information decreases in time. This definition implies that learning enables the system to optimize its responses upon external stimuli such that its expected profit increases. A physical model is discussed where the system's subjective probabilities, which enter into the definition of its missing information, can be considered as internal physical parameters. It is conjectured that the same might be true in models of brain and memory. Two forms of the associative memory model are briefly discussed.
35 citations
TL;DR: An investigation of the relationship between the amplitudes and rise times of the miniature end-plate potentials recorded from the neuromuscular junctions of the frog sartorius has shown the existence of a positive correlation between these two parameters.
Abstract: An investigation of the relationship between the amplitudes and rise times of the miniature end-plate potentials recorded from the neuromuscular junctions of the frog sartorius has shown the existence of a positive correlation between these two parameters. This finding is consistent with the occurrence of a process of “spreading activation”, i.e. the progressive recruitment of end-plate receptors by a wave of acetylcholine molecules diffusing tangentially within the synaptic space. It appears that the initial concentration of transmitter molecules within the synaptic cleft must be large enough to saturate the receptors of the end-plate membrane, immediately subjacent to the site of release. This idea is supported by the result of calculations using a highly simplified model of the myoneural junction.
22 citations
TL;DR: A micro method for the detection of LDH isoenzymes by isoelectric focussing in 5 μl capillaries by using tetrazolium staining mixture with lactate as the substrate is described.
Abstract: A micro method for the detection of LDH isoenzymes by isoelectric focussing in 5 μl capillaries is described The isoenzymes are visualized by incubating microgels in a tetrazolium staining mixture with lactate as the substrate The method is very sensitive allowing LDH isoenzyme activity to be determined in only a few μg of wet weight tissue The procedure is used to demonstrate the LDH isoenzyme patterns in fifteen different regions of the rabbit brain
IBM1
TL;DR: In an attempt to define patterns in the output of a neuron in the central nervous system, an inequality test for differences in the width of adjacent pairs of interspike intervals was performed using a digital computer.
Abstract: In an attempt to define patterns in the output of a neuron in the central nervous system, an inequality test for differences in the width of adjacent pairs of interspike intervals was performed using a digital computer. The results of the tests, whether the first interval was longer (+), shorter (-), or the same duration (0) as the second, were arranged into a conditional probability matrix which showed the sequential relationships between three adjacent intervals. The probabilities can be denned as the transition probabilities for an output of a neuron going from one state to another. Significant diagram patterns emerged.
TL;DR: The author describes studies concerned with the timing and the coding of output from pyramidal tract neurons of the motor cortex during learned movement to understand the way in which the different components of the motors are related to each other and to the performance of the range of learned movements which constitute complex behavior.
Abstract: The author describes studies concerned with the timing and the coding of output from pyramidal tract neurons of the motor cortex during learned movement. The goal is to understand in addition, the way in which the different components of the motor system are related to each other and to the performance of the range of learned movements which constitute complex behavior.
TL;DR: A precise regional response specificity was identified within the frontal cortex while corpus callosum depth was increased and diencephalic width decreased by environmental enrichment.
Abstract: Rearing animals under conditions of environmental enrichment has been shown to induce depth increases in the cerebral cortex. The nature of these increases is not simple since a variety of regional and temporal patterns are apparent and on e report indicated an actual decreased depth of the medial frontal cortex following 80 days of enrichment. in the present study the depth of this medial frontal cortex was measured in three separate experiments and the dimensions of adjacent cortex, and subcortex were also examined. A precise regional response specificity was identified within the frontal cortex while corpus callosum depth was increased and diencephalic width decreased by environmental enrichment.
TL;DR: Only small amounts of a- methyl-catecholamines were formed in the optic lobes of Octopus vulgaris following a-methylDOPA treatment, and the dose of reserpine required to produce similar decreases in amine concentrations in the ganglia of Helix pomatia was more than 10 times higher.
Abstract: 1. Reserpine produced a marked decrease in the concentration of dopamine (DM), noradrenaline (NA) and 5-hydroxytryptamine (5-HT) in the optic lobes of Octopus vulgaris. This depletion was detected 6–12 hours after drug treatment and lasted for at least 16 days. The dose of reserpine required to produce similar decreases in amine concentrations in the ganglia of Helix pomatia was more than 10 times higher.2. After L-DOPA administration, the amino acid was detectable for at least two days in the ganglia of Helix pomatia. The treatment led to an increase in the concentration of DM but not that of NA.3. a-Methyl-dopamine (a-methylDM) was found in the ganglia of Helix pomatia after a-methylDOPA administration but a-methyl-noradrenaline (a-methylNA) was not detected. Following the a-methylDOPA treatment, the amino acid remained detectable in Helix pomatia ganglia for at least three days.4. Only small amounts of a-methyl-catecholamines were formed in the optic lobes of Octopus vulgaris following a-methylDOPA adm...
TL;DR: It is concluded that Ba is a poor substitute for Ca in accelerating MEPP frequency in Ca-free solutions, but Ba ccelerates release if Ca is also present, which is probably due to its membrane depolarizing action.
Abstract: Electrophysiological monitoring of transmitter release from nerve terminals in rat diaphragm muscles showed that substitution of Ba for Ca produced an initial transient increase in miniature end-plate potential (MEPP) frequency, followed by a decline in frequency to a rate expected in Ca-free solutions. When Ba is added to solutions with up to 2.5 mM Ca, Ba increases MEPP frequency. Part of this acceleratory action of Ba is probably due to its membrane depolarizing action. At higher concentrations of Ca, Ba reduces MEPP frequency. A direct action of Ba in accelerating MEPP frequency is observed when membrane potential is stabilized at higher Ba concentrations in the presence of Ca. It is concluded that Ba is a poor substitute for Ca in accelerating MEPP frequency in Ca-free solutions, but Ba ccelerates release if Ca is also present.
TL;DR: It is found that another oxidizing reagent, o-iodosobenzoic acid exerts an extremely powerful and reversible depolarizing action on the end-plate membrane.
Abstract: Three types of SH reagents depolarize the end-plate membrane: oxidant agents, organic mercurials and heavy metal ions (Hg++ in particular). The similarity of the effects of such different compounds suggested that whenever certain key SH groups are disturbed or diverted from their free, reduced condition, the receptor protein undergoes a change which results in an increased membrane conductance.We have found that another oxidizing reagent, o-iodosobenzoic acid exerts an extremely powerful and reversible depolarizing action on the end-plate membrane. It was possible, in consequence, to study how d-tubocurarine and tetraethylammonium chloride interfere with its effects. The results obtained suggest that the SH groups which have the ability to induce activation are located at or near the binding site of the cholinergic receptor.
TL;DR: The way in which the adaptability and reliability of biological systems is connected to their uncertainty about the environment is discussed, which provides a basis for analyzing patterns of biological adaptable and their relation to the organization and evolution of Biological systems, including the evolution of the nervous system.
Abstract: This paper discusses the way in which the adaptability and reliability of biological systems is connected to their uncertainty about the environment. This provides a basis for analyzing patterns of biological adaptability and their relation to the organization and evolution of biological systems, including the evolution of the nervous system.
TL;DR: It was found that α activity in ventral root filaments to both extensor and flexor muscles was depressed and that this depression was not only independent of the previously described γ effects but differed from them in various respects.
Abstract: The effect of vagal afferent firing, evoked by veratridine and phenyldiguanide, on the reflex responses of lumbosacral a motoneurons to muscle stretch (stretch reflex) and to electrical stimulation of muscle (monosynaptic reflex) and skin nerves (polysynaptic reflex) was investigated in cats under light chloralose-urethane anesthesia in the absence of fusimotor spindle feedback. It was found that α activity in ventral root filaments to both extensor and flexor muscles was depressed and that this depression was not only independent of the previously described γ effects but differed from them in various respects. Unlike the γ depression, α depression was infrequently preceded by an initial increase in activity. Thus, α depression often was already present when γ firing went through its early phase of acceleration. Furthermore, α depression was sometimes seen in the absence of γ effects. 5HT which had predominantly increased γ firing, produced a depression of α activity. Determination of the latent periods o...
TL;DR: The unique properties of the Phycomyces photosensory system are presented and discussed and stress is layed on the importance of this system as an experimental organism for the study of a variety of sensory phenomena.
Abstract: The unique properties of the Phycomyces photosensory system are presented and discussed. Stress is layed on the importance of this system as an experimental organism for the study of a variety of sensory phenomena.
TL;DR: A new technique of analysis of neuronal interspike intervals is proposed which is based on the concept of serial correlation, and gives an estimate of the relationship between a particular interval and an interval that is removed from it by a fixed number of other intervals specified by a particular lag value.
Abstract: In the present study we propose a new technique of analysis of neuronal interspike intervals which we termed the interdependence series matrix. This method is based on the concept of serial correlation, and gives an estimate of the relationship between a particular interval and an interval that is removed from it by a fixed number of other intervals specified by a particular lag value.
TL;DR: The discussion presented deals with the question of the existence of a neural code for learning, and what parameters of nerve impulses might be involved in encoding at least one kind of avoidance learning.
Abstract: The discussion presented deals with the question of the existence of a neural code for learning. What parameters of nerve impulses might be involved in encoding at least one kind of avoidance learning ?
TL;DR: The paper explores the properties of several kinds of system description as a framework within which to formulate and solve basic biological problems; their scope, their limitations and the relationships between them.
Abstract: The paper explores the properties of several kinds of system description which have been employed as a framework within which to formulate and solve basic biological problems; their scope, their limitations and the relationships between them.
TL;DR: In this article, the authors evaluated patients with unilateral left or right temporal lobectomy on several visual tasks demanding perception and memory for verbal and nonverbal information, and found that the left and right temporal patients commanded an intact immediate memory span for a long string of verbal or nonverbal material, but when the test memoranda exceeded this memory span, dissociable deficits appeared; the left temporal patients did poorly with verbal items, the right, with non verbal information.
Abstract: Patients with unilateral left or right temporal lobectomy were evaluated on several visual tasks demanding perception and memory for verbal and nonverbal information. Recognition thresholds for words and random patterns projected tachistoscopically to the central visual field did not reveal a perceptual disorder for either temporal group. Also, the left and right temporal patients commanded an intact immediate memory span for a long string of verbal or nonverbal material. However, when the test memoranda exceeded this memory span, dissociable deficits appeared; the left temporal patients did poorly with verbal items, the right, with nonverbal information. The findings support the verbal-nonverbal distinction for mnemonic processes assigned to the left and right temporal lobes in man. Although immediate registration and short-term storage of information are unimpaired by temporal lobe injury, temporal lesions constrict the hold mechanism, and the amount of information that can be retained for a long period...
TL;DR: Acetylcholinesterase (AChE) was demonstrated histochemically in the nervous system of the snail, Biomphalaria glabrata, and can be observed also in the entire cross sections of the axons.
Abstract: Acetylcholinesterase (AChE) was demonstrated histochemically in the nervous system of the snail, Biomphalaria glabrata.AChE activity is localized in two distinct regions in each buccal ganglion.AChE activity is high in the neuropiles of cerebral and pedal ganglia; in a few instances, AChE activity is associated with axons in the neuropiles. In the pleural, visceral and parietal ganglia, AChE activity seems to be highly localized structurally.AChE activity of each ganglion is in communication with one another via connectives and commissures.AChE activity is distributed throughout the motor nerves of the snail foot, and is not exclusively associated with membranes, but can be observed also in the entire cross sections of the axons.
TL;DR: It is demonstrable that the definition of the concept of neural energy, in accordance with its physical analogy, is advantageous from the standpoint of the treatment of information capacity and the information transfer properties of simple neural systems.
Abstract: A Computer simulation of open neural systems, of which the mathematical treatment is almost impossible, has revealed entropy behaviour generally similar to that of the closed systems. However, the entropy value is dependent upon the temporal pattern of the input energy. This dependence is in accordance with the hypothesis made: the difference between the state of the system and the state at maximum entropy grows with the input information per unit of input energy. It is thus demonstrable that the definition of the concept of neural energy, in accordance with its physical analogy, is advantageous from the standpoint of the treatment of information capacity and the information transfer properties of simple neural systems.
TL;DR: Information processing in the nervous system is based essentially on the existence of highly organized specific connections, and the persistence of these circuits can be best explained by the formation of specific molecular markers.
Abstract: Information processing in the nervous system is based essentially on the existence of highly organized specific connections. While innate information is coded in terms of prewired circuits, learned information probably involves the creation of new connections between the existing pathways to establish an acquired circuit, representing the memory trace. The persistence of these circuits can be best explained by the formation of specific molecular markers. One of these coded substances has been isolated, identified as a pentadecapeptide and reproduced by synthesis.