The differential synaptic organization of the spinal and lemniscal projections to the ventrobasal complex of the rat thalamus. Evidence for convergence of the two systems upon single thalamic neurons

Neuroscience ◽  
1987 ◽  
Vol 22 (3) ◽  
pp. 925-934 ◽  
Author(s):  
W. Ma ◽  
M. Peschanski ◽  
H.J. Ralston
Keyword(s):  
Synaptic Organization ◽  
Thalamic Neurons ◽  
Ventrobasal Complex ◽  
Two Systems

SCALING BEHAVIOR OF THE DENDRITIC BRANCHES OF THALAMIC NEURONS

Fractals ◽  
1993 ◽  
Vol 01 (02) ◽  
pp. 171-178 ◽  
Author(s):  
KLAUS-D. KNIFFKI ◽  
MATTHIAS PAWLAK ◽  
CHRISTIANE VAHLE-HINZ
Keyword(s):  
Growth Process ◽  
Scaling Law ◽  
Branching Ratio ◽  
Scaling Behavior ◽  
Neuronal Growth ◽  
Thalamic Neurons ◽  
Dendritic Trees ◽  
Ventrobasal Complex ◽  
Dendritic Branches

The morphology of Golgi-impregnated thalamic neurons was investigated quantitatively. In particular, it was sought to test whether the dendritic bifurcations can be described by the scaling law (d0)n=(d1)n+(d2)nwith a single value of the diameter exponent n. Here d0 is the diameter of the parent branch, d1 and d2 are the diameters of the two daughter branches. Neurons from two functionally distinct regions were compared: the somatosensory ventrobasal complex (VB) and its nociceptive ventral periphery (VBvp). It is shown that for the neuronal trees studied in both regions, the scaling law was fulfilled. The diameter exponent n, however, was not a constant. It increased from n=1.76 for the 1st order branches to n=3.92 for the 7th order branches of neurons from both regions. These findings suggest that more than one simple intrinsic rule is involved in the neuronal growth process, and it is assumed that the branching ratio d0/d1 is not required to be encoded genetically. Furthermore, the results support the concept of the dendritic trees having a statistically identical topology in neurons of VB and VBvp and thus may be regarded as integrative modules.

Responses of thalamic neurons in rats to skin cooling and hypothalamic temperature

1989 ◽  
Vol 256 (6) ◽  
pp. R1293-R1298
Author(s):  
Y. Sakata ◽  
A. Morimoto ◽  
N. Murakami
Keyword(s):  
Digital Signals ◽  
Cold Stimulation ◽  
Thalamic Neurons ◽  
Hypothalamic Temperature ◽  
Analog Signals ◽  
Ventrobasal Complex ◽  
Graded Response ◽  
Skin Cooling ◽  
Specific Localization ◽  
Marginal Region

The responses of rat thalamic neurons to skin cooling were electrophysiologically examined. The responses of cold-excited neurons were classified into two types. One is a steplike response in which the activity abruptly increases with skin cooling, and the other is a graded response in which the activity gradually increases with skin cooling. The sites of these neurons were histologically identified in the ventrobasal complex of the thalamus, ventrolateral thalamus, and posterior thalamus. Two-thirds of them were found in a marginal region of the ventrobasal complex. There is no specific localization between the sites of thalamic neurons showing the steplike response and those showing the graded response. Furthermore, the effects of hypothalamic temperature on the thalamic neurons responding to skin cooling were observed. The response of thalamic neurons to cold stimulation of the skin was markedly suppressed during the hypothalamic warming. These results show that the steplike response is related to converting thermal analog signals to digital signals and that the graded response is related to relaying analog patterns of cold signals. Thermal afferent signals are modulated by hypothalamic temperature and subsequently cold sensation is modulated.

Nonhuman sequence learning findings argue against Hoerl and McCormack's two systems of temporal cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Benjamin J. De Corte ◽  
Edward A. Wasserman
Keyword(s):  
Sequence Learning ◽  
Past Research ◽  
Ordinal Position ◽  
Temporal Cognition ◽  
Two Systems

Abstract Hoerl & McCormack propose that animals learn sequences through an entrainment-like process, rather than tracking the temporal addresses of each event in a given sequence. However, past research suggests that animals form “temporal maps” of sequential events and also comprehend the concept of ordinal position. These findings suggest that a clarification or qualification of the authors’ hypothesis is needed.

Synaptic organization of the gustatory NST

1994 ◽  
Vol 52 ◽  
pp. 150-151
Author(s):  
M. C. Whitehead
Keyword(s):  
Central Nervous System ◽  
Dendritic Spines ◽  
Fundamental Problem ◽  
Cell Types ◽  
Brain Regions ◽  
Excitatory Synapses ◽  
Solitary Tract ◽  
Synaptic Organization ◽  
Synaptic Junctions ◽  
Afferent Terminals

A fundamental problem in taste research is to determine how gustatory signals are processed and disseminated in the mammalian central nervous system. An important first step toward understanding information processing is the identification of cell types in the nucleus of the solitary tract (NST) and their synaptic relationships with oral primary afferent terminals. Facial and glossopharyngeal (LIX) terminals in the hamster were labelled with HRP, examined with EM, and characterized as containing moderate concentrations of medium-sized round vesicles, and engaging in asymmetrical synaptic junctions. Ultrastructurally the endings resemble excitatory synapses in other brain regions.Labelled facial afferent endings in the RC subdivision synapse almost exclusively with distal dendrites and dendritic spines of NST cells. Most synaptic relationships between the facial synapses and the dendrites are simple. However, 40% of facial endings engage in complex synaptic relationships within glomeruli containing unlabelled axon endings particularly ones termed "SP" endings. SP endings are densely packed with small, pleomorphic vesicles and synapse with both the facial endings and their postsynaptic dendrites by means of nearly symmetrical junctions.

Comparison of two devices for measuring exercise transcutaneous oxygen pressures in patients with claudication

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  
Keyword(s):  
Oxygen Pressure ◽  
Optical Sensors ◽  
Chemical Sensors ◽  
Transcutaneous Oxygen ◽  
Starting Values ◽  
Two Systems ◽  
Transcutaneous Oxygen Pressure ◽  
New Sensors ◽  
Changes Over Time ◽  
Over Time

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.

A Tale of Two Systems: Trauma and Behavioral and Physical Health Status in Child Welfare and Juvenile Justice Youth

2014 ◽  
Author(s):  
Erynne H. Shatto ◽  
Sarah J. Fucillo ◽  
Z. Kane Jones ◽  
James R. Stefurak ◽  
Valerie Bryan
Keyword(s):  
Health Status ◽  
Child Welfare ◽  
Juvenile Justice ◽  
Physical Health ◽  
Physical Health Status ◽  
Two Systems

Two systems for emotional action processing

2013 ◽  
Author(s):  
Joanna Wincenciak ◽  
Jennifer Ingham ◽  
Tjeerd Jellema ◽  
Nick E. Barraclough
Keyword(s):  
Action Processing ◽  
Two Systems

Self-Damping Mechanism in Blood Coagulation

1974 ◽  
Vol 32 (01) ◽  
pp. 057-064 ◽  
Author(s):  
Y Nemerson ◽  
S.A Silverberg ◽  
J Jesty
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Calcium Ions ◽  
Control Mechanism ◽  
Factor Vii ◽  
Damping Factor ◽  
Factor V ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Two Systems

SummaryTwo reactions of the extrinsic pathway of coagulation, the activations of Factor X and prothrombin, have been studied in purified systems and shown to be self-damping. Factor X was activated by the tissue factor - Factor VII complex, and prothrombin by two systems: the coagulant protein of Taipan venom, and the physiological complex of activated Factor X, Factor V, lipid, and calcium ions. In each case the yield of enzyme, activated Factor X or thrombin, is a function of the concentration of activator. These and other observations are considered as a basis for a control mechanism in coagulation.

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