Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Differential roles of monkey striatum in learning of sequential hand movement (1997)
    Springer
    Experimental brain research 115 (1997), S. 1-5 
    Details
    ISSN: 1432-1106
    Keywords: Key words Procedural learning ; Basal ganglia ; Caudate ; Putamen ; Muscimol ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  To study the role of the basal ganglia in learning of sequential movements, we trained two monkeys to perform a sequential button-press task (2×5 task). This task enabled us to examine the process of learning new sequences as well as the execution of well-learned sequences repeatedly. We injected muscimol (a GABA agonist) into different parts of the striatum to inactivate the local neural activity reversibly. The learning of new sequences became deficient after injections in the anterior caudate and putamen, but not the middle-posterior putamen. The execution of well-learned sequences was disrupted after injections in the middle-posterior putamen and, less severely, after injections in the anterior caudate/putamen. These results suggest that the anterior and posterior portions of the striatum participate in different aspects of learning of sequential movements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00005669
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Axonal projection of prepositus hypoglossi and reticular neurons in the brainstem of the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 441-451 
    Details
    ISSN: 1432-1106
    Keywords: Nucleus prepositus hypoglossi ; Reticular formation ; Abducens nucleus ; Oculomotor nucleus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Extracellular unit spikes responsive to horizontal head rotation were recorded in and around the cat nucleus prepositus hypoglossi. Type II neurons (activated by contralateral angular acceleration) were much more common than type I neurons. The axonal projections of single prepositus and reticular neurons to the rostral brainstem were investigated by a systematic survey of antidromic responses using microstimulation. 2. Most type II prepositus and reticular neurons sent axons to the rostral brainstem either ipsilaterally or contralaterally (i-type II or c-type II neurons). The stem axons ran through the reticular formation without forming a discrete fiber tract, usually reaching the midbrain tegmentum. 3. Axons of type II prepositus and reticular neurons were presumed to terminate in some of the following areas: the contralateral prepositus and reticular region, pontine reticular formation, raphe nucleus, pontine tegmental reticular nucleus, midbrain reticular formation, and lateral midbrain tegmentum near the parabigeminal nucleus. 4. The possibility of efferent connections to the abducens and oculomotor nuclei was closely examined. Some of type II prepositus and reticular neurons (24%) sent axonal branches into the abducens nucleus on the ipsi- or contralateral side. The ramification of such axonal branches seemed to be poor. Axonal projection to the oculomotor nuclei was also observed but less commonly (5%).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Inhibitory connections of nystagmus-related reticular burst neurons with neurons in the abducens, prepositus hypoglossi and vestibular nuclei in the cat (1980)
    Springer
    Experimental brain research 39 (1980), S. 301-311 
    Details
    ISSN: 1432-1106
    Keywords: Inhibitory burst neuron ; Reticular formation ; Abducens internuclear interneuron ; Prepositus hypoglossi neuron ; Vestibular neuron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Action potentials of inhibitory burst neurons (IBNs) were extracellularly recorded in the pontomedullary reticular formation in the cat. These neurons were identified by their burst activity coincident with the quick inhibitory phase of the contralateral abducens nerve during vestibular nystagmus and by their antidromic activation from the contralateral abducens nucleus. During extracellular recording from the soma of single IBNs, another electrode for microstimulation was systematically tracked throughout the brain stem. For each IBN investigated, the effective sites for antidromic activation were invariably found in the contralateral abducens, prepositus hypoglossi, medial vestibular nuclei and the area ventral to the prepositus hypoglossi nucleus. Stimulation of neither the ipsilateral brain stem nor the oculomotor nuclei evoked antidromic responses in IBNs. Extracellular spikes of single IBNs and neurons in the overlying projection area were recorded simultaneously. Their correlation was examined by using peri-spike time histograms. Shortly after the spikes of single IBNs, the activity of motoneurons and internuclear interneurons in the abducens nucleus, and of type II neurons in the prepositus hypoglossi and vestibular nuclei, was depressed. Connections of IBNs with ipsilateral medial rectus motoneurons were studied by spike-triggered averaging of membrane potentials of the motoneurons and action potentials of the medial rectus nerve. Single IBN spikes induced a di- or polysynaptic disfacilitation in the motoneurons. This disfacilitation was concluded to be mediated by some of the above-described interneurons which were directly inhibited by IBNs. Their depressant effect on medial rectus motoneuronal spike activity was comparable to that on the spike activity of contralateral abducens motoneurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237119
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Saccadic eye movements following injection of lidocaine into the superior colliculus (1986)
    Springer
    Experimental brain research 61 (1986), S. 531-539 
    Details
    ISSN: 1432-1106
    Keywords: Superior colliculus ; Saccades ; Eye movements ; Behaving monkey ; Lidocaine injection ; Reversible lesion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ablation of the superior colliculus (SC) has generally produced limited deficits in the initiation of saccadic eye movements, usually an increase in the latency of saccades. However, recent studies using muscimol, a GABA agonist, to block afferents to the SC showed deficits in not only latency but in amplitude and velocity of saccades as well. These greater deficits might be dependent upon the testing of saccades shortly after the damage of SC before any compensation for the deficits could develop. The present experiments tested this hypothesis by injecting a local anesthetic into SC. The anesthetic inactivated the cells entirely rather than just deafferenting them, but still allowed testing immediately after the injection. Clear deficits were observed following injection of lidocaine into the SC. The amplitudes of saccades to visual targets were shortened, and the peak velocities of the saccades were reduced even if the reduced amplitude of the saccades was taken into account. Latency of saccades usually increased. The deficits were limited to the area of the visual field that overlapped the movement fields of the cells near the injection site. If the movement fields were in the periphery, saccades to the periphery were shortened following the injection of lidocaine. If the movement fields were near the center of gaze, saccades into the area were shortened, but the monkey was able to make saccades over the visual field related to the affected area to more peripheral targets. These experiments support the view that the SC normally conveys information on the amplitude and velocity of saccadic eye movements, but that gradual compensation can be made over time by other pathways when damage to the structure occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237578
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Characteristics of a long-term procedural skill in the monkey (1998)
    Springer
    Experimental brain research 118 (1998), S. 293-297 
    Details
    ISSN: 1432-1106
    Keywords: Key words Procedural memory ; Sequential movements ; Memory transfer ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The purpose of this study was to characterize the nature and structure of procedural memory. We have previously studied the process of learning sequential behavioral procedures using monkeys. The monkey’s task was to press five consecutive pairs of buttons (indicated by illumination) in the correct order for every pair, which he had to find by trial-and-error in a block of trials. The whole sequence was called a “hyperset”; each pair was called a “set”. We first examined whether monkeys learned to perform a hyperset as a single sequence or learned the order of button-presses individually for each set. To answer this question, we generated hypersets that were the same as the hypersets that had been extensively learned except that the order of the sets was reversed. The performance of these “reversed hypersets” was much worse than the performance of the original learned hypersets and was similar to the performance of new hypersets, as regards both the number of errors and the performance time. The result suggests that monkeys learned a hyperset as a sequence. To examine whether the learned performance was specific to the hand used for practice, we had monkeys use the same hand throughout the long-term practice of each hyperset, and then tested the opposite hand. The performance using the opposite hand was worse than the performance using the trained hand, but was better than the performance for new hypersets. This indicates that the memory for the sequential procedure is only partially accessible to the hand that was not used for the practice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050284
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Cervical effects on abducens motoneurons and their interaction with vestibulo-ocular reflex (1973)
    Springer
    Experimental brain research 18 (1973), S. 512-530 
    Details
    ISSN: 1432-1106
    Keywords: Cervical afferents ; Abducens motoneuron ; Interneuron ; Vestibular nuclei
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of neck afferents on abducens motoneurons and their interaction with the vestibulo-abducens reflex were examined in chloraloseanesthetized or unanesthetized, decerebrate cats. The test reflex elicited in the abducens nerve by stimulation of the contralateral vestibular nerve was inhibited by contralateral and facilitated by ipsilateral cervical dorsal root or neck joint stimulation. These reciprocal effects were obtained by stimulation at the level of C2 and C3, but not from C5 or lower. Contralateral and ipsilateral cervical stimulation induced IPSPs and EPSPs, respectively, in abducens motoneurons. The latencies were 2.8–6.0 msec for the IPSP and 2.8–5.3 msec for the EPSP after stimulation of the dorsal root. The labyrinthine-induced disynaptic IPSP or EPSP was facilitated by conditioning stimulation of the contralateral and ipsilateral cervical dorsal root, respectively. It is thus postulated that the cervico-abducens and vestibuloabducens reflex pathways converge upon common inhibitory or excitatory interneurons in the vestibular nuclie. Labyrinthine- and cervical-induced responses of the presumed interneurons in the vestibular nuclei or those of their axons recorded in the abducens nuclie were consistent with the above view. Lesion experiments in the brain stem indicated that afferent volleys from the neck joint ascend ipsilaterally in the spinal cord, cross to the contralateral side in the brain stem, and eventually project to the vestibular nuclei, thus interacting with the vestibulo-ocular reflex activity. A possible functional role of the cervical effects on the ocular motoneuron was briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234135
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Presynaptic impulses in the abducens nucleus and their relation to postsynaptic potentials in motoneurons during vestibular nystagmus (1977)
    Springer
    Experimental brain research 27 (1977), S. 355-376 
    Details
    ISSN: 1432-1106
    Keywords: Vestibular nystagmus ; Abducens motoneuron ; Presynaptic impulse ; Vestibular neuron ; Burst neuron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Unit spikes of axons projecting to the abducens nucleus and responding to horizontal rotation of the head were recorded within the cat abducens nucleus. Their discharge pattern related to vestibular nystagmus was investigated with reference to PSP changes of abducens motoneurons as monitored by the field potentials in the nucleus. There were four groups of presynaptic axons whose activity was tightly related to motoneuronal PSPs. 2. The first and second groups of axons were activated mono- and disynaptically from the contralateral labyrinth, respectively, and fired in phase with abducens nerve discharges. Their tonic activity during the slow excitatory phase of motoneurons was abruptly suppressed at the onset of positive field potential (motoneuronal hyperpolarization). The disynaptically activated axons exhibited burst-tonic discharges at the quick excitatory phase and steep increases in their discharge frequency were synchronous with the onset of negative field potential (motoneuronal depolarization). 3. The third group was activated monosynaptically from the ipsilateral labyrinth and fired in phase with the silent period of the abducens nerve. Their tonic activity during the slow inhibitory phase of motoneurons was abruptly silenced at the onset of negative field potential. At the quick inhibitory phase they tended to begin firing slightly later than the onset of positive field potential. 4. The fourth group exhibited high frequency burst discharges at the quick inhibitory phase of motoneurons. Steep increases in discharge frequency occurred synchronously with the onset of the positive field potential. These axons were silent during the slow inhibitory phase of motoneurons. 5. The characteristic time course of PSPs in abducens motoneurons during vestibular nystagmus was well explained by synaptic actions of these four groups of presynaptic axon on motoneurons. The origin of each group of axon was discussed in view of their responses to electric stimulation of the vestibular nerve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235510
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Converging patterns of finger representation and complex response properties of neurons in area 1 of the first somatosensory cortex of the conscious monkey (1983)
    Springer
    Experimental brain research 51 (1983), S. 327-337 
    Details
    ISSN: 1432-1106
    Keywords: Postcentral gyrus ; Area 1 ; Finger representation ; Neural integration ; Monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The representation of the hand and fingers in area 1 of the first somatosensory cortex was studied in conscious monkeys by recording single neuronal activity. The results are as follows. (1) We found multi-finger type receptive fields which cover more than one finger discontinuously or wide-field type ones which cover both finger and palmar skin or two halves of the palmar skin together. Multi-finger type receptive fields were also found in some joint manipulation neurons. Multifinger or wide-field type receptive fields were found in nearly 40% of area 1 neurons. The rate was even higher, up to 70%, in the medial part of the cortical finger region. Consequently, the finger representation in area 1 was less discretely somatotopic than that in area 3b. (2) The submodality content of area 1 was almost identical to that of area 3b: 74.5% and 20.9% of identified neurons were, respectively, cutaneous and deep. The distribution of neurons with different submodalities overlapped in area 1. (3) Among area 1 neurons with multi-finger type receptive fields, response characteristics of those with inhibitory receptive fields, those with directional selectivity to moving stimuli, and those with converging afferent inputs, were studied in detail. Evidence is presented to suggest that information from different parts of the body, or from the same body parts but different afferent sources, is integrated in area 1. (4) It is proposed that, within the SI, area 1 is the initial stage of integration of sensory information coming from the thalamus and from area 3a or 3b via cortico-cortical connections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237869
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Diversity in receptive field properties of vertical neuronal arrays in the crown of the postcentral gyrus of the conscious monkey (1985)
    Springer
    Experimental brain research 58 (1985), S. 400-411 
    Details
    ISSN: 1432-1106
    Keywords: Monkey ; Postcentral gyrus ; Finger representation ; Vertical neuronal arrays ; Converging inputs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single neuronal activity was recorded in the crown of the postcentral gyrus (areas 1 and 2) in 5 conscious monkeys. A total of 93 penetrations were made in the hand and finger region of 9 hemispheres and 827 neurons were isolated. The receptive field characteristics of neurons recorded along each of 88 penetrations which entered perpendicularly to the cortical surface were compared. The majority of neurons in this region were responsive to skin stimulation. In 54 penetrations, neurons related to different sensory submodalities were mixed. In 30, skin neurons predominated, and in 8, ‘deep’ neurons, while in the remaining 16 penetrations neurons related to different submodalities were equally mixed. In 16 penetrations, neurons responded exclusively to stimulation of skin, hair or nails. In 9 penetrations, neurons were exclusively related to joint manipulation or other types of ‘deep’ submodality. In 9 penetrations, unidentified neurons were in the majority. In each penetration, the receptive field positions varied considerably on the same finger or encompassed more than one finger. Although neurons of the same submodality, either skin or ‘deep’ tended to be set in an array, the most adequate stimulus could vary among neurons of a given array. The variability in the receptive field positions or the most adequate stimuli remained constant irrespective of the angle of the electrode penetration in the cortex. The results are compatible with the idea that vertically arranged neuronal array receive inputs of multiple sources, both thalamacortical and corticocortical, so that interactions between different inputs can readilly occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235321
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Vertical neuronal arrays in the postcentral gyrus signaling active touch: a receptive field study in the conscious monkey (1985)
    Springer
    Experimental brain research 58 (1985), S. 412-420 
    Details
    ISSN: 1432-1106
    Keywords: Monkey ; Postcentral gyrus ; Vertical neuronal arrays ; Functional surfaces ; Active touch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single neuronal activity was recorded in the crown of the postcentral gyrus (areas 1 and 2) in 5 conscious monkeys. A total of 88 penetrations entered perpendicularly to the cortical surface. Among them, 6 examples are chosen and the receptive field characteristics of constituent neurons were described in some detail. Receptive fields of neurons recorded along a particular penetration were variable in their positions, but the largest receptive field usually covered the others. Neurons with the largest receptive fields were found most frequently in the infragranular layers. Often they included inhibitory receptive fields. The inhibitory receptive fields were arranged side-by-side to the excitatory ones, rather than in a center-surround fashion. The key stimulus common to neurons in a vertical penetration was the contact of an object to the receptive field achieved during animal's active behavior to manipulate the object. We thus designated the largest receptive field as a functional surface. Our results demonstrate that a vertical array of neurons in this cortical region can be regarded as a functional assemblage which deals with a set of information concerning one of various aspects of active touch.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235322
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...