[Functional Parcellation of Frontal Higher Order Motor Cortex].

Motor areas in the frontal cortex are classified into medial and lateral functional groups. The dorsal premotor areas in the lateral groups are involved in motor guidance based on behavioral rules. The ventral premotor cortex contributes to motor guidance relying on spatial aspects of sensory information.

Similarity in Neuronal Firing Regimes across Mammalian Species.

Unlabelled: The architectonic subdivisions of the brain are believed to be functional modules, each processing parts of global functions. Previously, we showed that neurons in different regions operate in different firing regimes in monkeys. It is possible that firing regimes reflect differences in underlying information processing, and consequently the firing regimes in homologous regions across animal species might be similar.

Neurons in the cingulate motor area signal context-based and outcome-based volitional selection of action.

Volitional selection of action is subject to continuous adjustment under the influence of information obtained by monitoring behavioral consequences and by exploiting behavioral context based on prior knowledge about the environment. The rostral cingulate motor area (CMAr) is thought to be responsible for adjusting behavior by monitoring its consequences. To investigate whether the CMAr also plays a role in exploitation of behavioral context in action selection, we recorded neuronal activities from the CMAr while monkeys performed a reward-based motor selection task that required them to switch from one action to the other based on the amount of reward.

Altered cognitive function of prefrontal cortex during error feedback in patients with irritable bowel syndrome, based on FMRI and dynamic causal modeling.

Background & Aims: Patients with irritable bowel syndrome (IBS) have increased activity in the insula and reduced activation of the dorsolateral prefrontal cortex (DLPFC) in response to visceral stimulation. We investigated whether they have latent impairments in cognitive flexibility because of dysfunction in the DLPFC and insula and altered connectivity between brain regions.

Methods: We analyzed data from 30 individuals with IBS (15 men; age, 21.

Deciphering elapsed time and predicting action timing from neuronal population signals.

The proper timing of actions is necessary for the survival of animals, whether in hunting prey or escaping predators. Researchers in the field of neuroscience have begun to explore neuronal signals correlated to behavioral interval timing. Here, we attempt to decode the lapse of time from neuronal population signals recorded from the frontal cortex of monkeys performing a multiple-interval timing task.

Deficits in action selection based on numerical information after inactivation of the posterior parietal cortex in monkeys.

A previous study identified neuronal activity in area 5 of the monkey posterior parietal cortex that reflects the numerosity of a series of self-performed actions. It is not known, however, whether area 5 is crucially involved in the selection of an action based on numerical information or, instead, merely reflects numerosity-related signals that originate in other brain regions. We transiently and focally inactivated area 5 to test its functional contributions to numerosity-based action selection.

Relating neuronal firing patterns to functional differentiation of cerebral cortex.

It has been empirically established that the cerebral cortical areas defined by Brodmann one hundred years ago solely on the basis of cellular organization are closely correlated to their function, such as sensation, association, and motion. Cytoarchitectonically distinct cortical areas have different densities and types of neurons. Thus, signaling patterns may also vary among cytoarchitectonically unique cortical areas.

Interval time coding by neurons in the presupplementary and supplementary motor areas.

Interval timing is an essential guiding force of behavior. Previous reports have implicated the prefrontal and parietal cortex as being involved in time perception and in temporal decision making. We found that neurons in the medial motor areas, in particular the presupplementary motor area, participate in interval timing in the range of seconds.

Spatial distribution of cingulate cortical cells projecting to the primary motor cortex in the rat.

We examined the location and spatial distribution of cingulate cortical cells projecting to the primary motor cortex (M1) in rats, using a double retrograde-labeling technique. The orofacial, forelimb, and hindlimb areas of M1 were physiologically identified based on the findings of intracortical microstimulation and single cell recording. Two different tracers, diamidino yellow and fast blue, were injected into two sites of M1 in each rat.

Concept-based behavioral planning and the lateral prefrontal cortex.

Many lines of evidence implicate the lateral prefrontal cortex (LPFC) in the executive control of behavior. In early studies, neuronal activity in this area was thought to retain information about forthcoming movements for a short period until they were executed. However, later studies have stressed its role in the cognitive aspects of behavioral planning, such as behavioral significance, behavioral rules and behavioral goals.

Categorization of behavioural sequences in the prefrontal cortex.

Although it has long been thought that the prefrontal cortex of primates is involved in the integrative regulation of behaviours, the neural architecture underlying specific aspects of cognitive behavioural planning has yet to be clarified. If subjects are required to remember a large number of complex motor sequences and plan to execute each of them individually, categorization of the sequences according to the specific temporal structure inherent in each subset of sequences serves to facilitate higher-order planning based on memory. Here we show, using these requirements, that cells in the lateral prefrontal cortex selectively exhibit activity for a specific category of behavioural sequences, and that categories of behaviours, embodied by different types of movement sequences, are represented in prefrontal cells during the process of planning.

Binary-coded monitoring of a behavioral sequence by cells in the pre-supplementary motor area.

To regulate the temporal structure of a series of behavioral sequences involving multiple actions, it is essential to monitor the progress of the entire behavioral process. To identify the involvement of three cortical motor areas in monitoring behavioral sequences, we examined neuronal activity while monkeys sequentially performed a series of motor tasks in accordance with a predetermined behavioral schedule that included a numerical structure. We found that neurons in the pre-supplementary motor area exhibited activity that appeared to monitor the performance of the behavioral trials in a binary-coded manner.

Prefrontal cortical cells projecting to the supplementary eye field and presupplementary motor area in the monkey.

We examined the location and spatial distribution of prefrontal cortical (PF) cells projecting to the supplementary eye field (SEF) and presupplementary motor area (pre-SMA) using a double retrograde-labeling technique in monkeys (Macaca fuscata). The SEF and pre-SMA were physiologically identified based on the findings of intracortical microstimulation and single cell recordings. Two fluorescent tracers, diamidino yellow and fast blue, were injected into the SEF and pre-SMA of each monkey.

Cingulate cortical cells projecting to monkey frontal eye field and primary motor cortex.

We compared the distribution of cingulate cortical cells projecting to the frontal eye field (FEF) and primary motor cortex (MI) using a multiple retrograde labeling technique. Two fluorescent tracers were injected into physiologically identified FEF and MI in each monkey. The location of cells projecting to the forelimb area of MI served to identify the rostral (CMAr) and caudal (CMAc) cingulate motor areas.

Differences in spiking patterns among cortical neurons.

Spike sequences recorded from four cortical areas of an awake behaving monkey were examined to explore characteristics that vary among neurons. We found that a measure of the local variation of interspike intervals, L(V), is nearly the same for every spike sequence for any given neuron, while it varies significantly among neurons. The distributions of L(V) values for neuron ensembles in three of the four areas were found to be distinctly bimodal.

New classification scheme of cortical sites with the neuronal spiking characteristics.

Multiple cortical areas are mutually compared on the bases of neuronal spiking characteristics measured through three dimensionless interspike interval statistical coefficients. The spike sequences were recorded from the prefrontal cortical area (PF), the pre-supplementary motor area (Pre-SMA), the supplementary motor area (SMA) and the rostral cingulate motor area (CMAr) of a behaving monkey performing a waiting period task. The distribution of three statistical coefficients is found to be largely dependent on the recording site.

Spatial distribution and density of prefrontal cortical cells projecting to three sectors of the premotor cortex.

The spatial distribution of prefrontal cortical cells projecting to three different sectors in the premotor cortex was examined. The cells projecting to the three sectors were distributed in separate regions in the dorsolateral prefrontal cortex with a small overlap. Cells projecting to the ventral sector were distributed in the lower bank of the principal sulcus (PS).

Numerical representation for action in the parietal cortex of the monkey.

The anterior part of the parietal association area in the cerebral cortex of primates has been implicated in the integration of somatosensory signals, which generate neural images of body parts and apposed objects and provide signals for sensorial guidance of movements. Here we show that this area is active in primates performing numerically based behavioural tasks. We required monkeys to select and perform movement A five times, switch to movement B for five repetitions, and return to movement A, in a cyclical fashion.

Effects of morphine on two types of nucleus raphe dorsalis neurons in awake cats.

Forty-nine neurons recorded within the nucleus raphe dorsalis (NRD) in awake cats were classified into 2 groups: 29 regularly firing (clock-like) and 20 irregularly firing (non-clock-like) neurons. Hardly any of the clock-like neurons were influenced either by noxious stimulation (0.1 ml of 5% formalin, s.

Arthritis induced in cat by sodium urate: a possible animal model for tonic pain.

An attempt has been made to determine whether cats rendered arthritic by the injection of monosodium urate (MSU) crystals (rod-shaped 40-130 micrometers length) into one knee joint capsule can be used as animal model of tonic (chronic) pain. A limp and a decrease in body weight supported by the injected hind leg's paw occurred approximately 1 h after the MSU (20 mg) injection, reached a maximum at 2-3 h, and lasted for more than 6 h before a gradual return to pre-injection levels. They were diminished by systemic administration and local (the dorsal part of the nucleus raphe dorsalis) application of morphine, this effect being blocked by naloxone.

Antinociceptive action of morphine and pentazocine on unit activity in the nucleus centralis lateralis, nucleus ventralis lateralis and nearby structures of the cat.

Single neuronal activity has been recorded extracellularly from the nucleus centralis lateralis (CL), ventralis lateralis (VL) and medialis dorsalis (MD) of the cat thalamus. The majority of the CL, VL and MD neurons were excited by nociceptive stimulation such as pinching the skin with serrated forceps and/or intra-arterial injection of bradykinin. The nociceptive neurons were also driven by non-nociceptive stimulation such as tap of deep tissues, bending hairs and an air-puff and/or joint rotation, and their receptive fields were large.