Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Principles of Neural Science

Brain-computer interfaces for communication and control.

The emergence of a unified cognitive moment relies on the coordination of scattered mosaics of functionally specialized brain regions. Here we review the mechanisms of large-scale integration that counterbalance the distributed anatomical and functional organization of brain activity to enable the emergence of coherent behaviour and cognition. Although the mechanisms involved in large-scale integration are still largely unknown, we argue that the most plausible candidate is the formation of dynamic links mediated by synchrony over multiple frequency bands.

The brainweb: phase synchronization and large-scale integration.

Prelude. Cycle 1. Introduction. Cycle 2. Structure defines function. Cycle 3. Diversity of cortical functions is provided by inhibition. Cycle 4. Windows on the brain. Cycle 5. A system of rhythms: from simple to complex dynamics. Cycle 6. Synchronization by oscillation. Cycle 7. The brain's default state: self-organized oscillations in rest and sleep. Cycle 8. Perturbation of the default patterns by experience. Cycle 9. The gamma buzz: gluing by oscillations in the waking brain. Cycle 10. Perceptions and actions are brain state-dependent. Cycle 11. Oscillations in the "other cortex:" navigation in real and memory space. Cycle 12. Coupling of systems by oscillations. Cycle 13. The tough problem. References.

Rhythms of the brain

One fundamental function of primary motor cortex (MI) is to control voluntary movements. Recent evidence suggests that this role emerges from distributed networks rather than discrete representations and that in adult mammals these networks are capable of modification. Neuronal recordings and activation patterns revealed with neuroimaging methods have shown considerable plasticity of MI representations and cell properties following pathological or traumatic changes and in relation to everyday experience, including motor-skill learning and cognitive motor actions. The intrinsic horizontal neuronal connections in MI are a strong candidate substrate for map reorganization: They interconnect large regions of MI, they show activity-dependent plasticity, and they modify in association with skill learning. These findings suggest that MI cortex is not simply a static motor control structure. It also contains a dynamic substrate that participates in motor learning and possibly in cognitive events as well.

https://www.uta.edu/rfmems/Telemetry/Implant%20Sensor/47185_Plasticity%20and%20primary%20motor%20cortex.pdf

Plasticity and primary motor cortex.

We investigated the occurrence and distribution of oscillatory activity in local field potentials (LFPs) recorded from the frontal motor cortex of behaving monkeys performing skilled voluntary movements. LFPs were recorded simultaneously from up to 12 sites distributed throughout motor cortex while monkeys performed a visually guided, instructed delay task using the wrist or digits. Oscillatory activity between 15 and 50 Hz was evident in the LFP recorded from both primary motor cortex and premotor areas. Oscillations occurred preferentially before the visual cue to initiate movement but were infrequent during movement. Oscillations typically stopped before movement initiation during the wrist task, although they often continued into the initial phases of movement during the digit task. The relationship of oscillations to task performance was consistent across trials over periods of many months, although the amplitude and duration of oscillations varied across trials and days. Interactions between pairs of LFP recordings, evaluated with cross-correlation analysis, revealed synchronous oscillations over long distances (> 7 mm) and across primary motor cortex and premotor recording sites. These studies demonstrate that oscillations recorded in the LFP in motor cortex during trained motor tasks are not related to the details of movement execution but may be related to aspects of movement preparation.

https://www.pnas.org/content/pnas/90/10/4470.full.pdf

Oscillations in local field potentials of the primate motor cortex during voluntary movement.

Donoghue, John P., Jerome N. Sanes, Nicholas G. Hatsopoulos, and Gyongyi Gaal. Neural discharge and local field potential oscillations in primate motor cortex during voluntary movements. J. Neuroph...

Neural Discharge and Local Field Potential Oscillations in Primate Motor Cortex During Voluntary Movements

Voluntary hand movements in humans involve the primary motor cortex (M1). A functional magnetic resonance imaging method that measures relative cerebral blood flow was used to identify a distributed, overlapping pattern of hand movement representation within the posterior precentral gyrus, which contains M1. The observed pattern resembles those reported in nonhuman primates and differs from a somatotopically organized plan typically used to portray human motor cortex organization. Finger and wrist movements activated a wide expanse of the posterior precentral gyrus, and representations for different finger movements overlapped each other and the wrist representation. Multiple sites of activation occurred in the precentral gyrus for all movements. The overlapping representations may mediate motor and cognitive functions requiring coordinated neural processing for finger and wrist actions rather than discrete control implied by somatotopic maps.

https://science.sciencemag.org/content/sci/268/5218/1775.full.pdf

Shared neural substrates controlling hand movements in human motor cortex

In the accompanying paper (Sanes et al. 1989), we demonstrated that the map of motor cortex (MI) output was reorganized when examined 1 week to 4 months after a motor nerve lesion in adult rats. The present experiments measured the extent of functional reorganization that occurs within the first hours after this lesion. Shifts in MI output were examined by testing the effect of stimulation at a site in MI vibrissa area before and up to 10 h after nerve section of the branches of the facial nerve that innervate the vibrissa. Immediately following nerve transection, no movement or forelimb EMG activity was evoked by intracortical electrical stimulation within the vibrissa area. Within hours of the nerve transection, however, stimulation elicited forelimb EMG responses that were comparable to those obtained by stimulating within the pre-transection forelimb area. Remapping of MI after nerve transection indicated that the forelimb boundary had shifted about 1 mm medially from its original location into the former vibrissa territory. Forelimb EMG could be evoked for up to 10 h within this reorganized cortex. These results indicated that the output circuits of MI can be quickly reorganized by nerve lesions in adult mammals.

Jerome N. Sanes

Papers

Plasticity and primary motor cortex.

Oscillations in local field potentials of the primate motor cortex during voluntary movement.

Neural Discharge and Local Field Potential Oscillations in Primate Motor Cortex During Voluntary Movements

Shared neural substrates controlling hand movements in human motor cortex

Dynamic organization of primary motor cortex output to target muscles in adult rats. II. Rapid reorganization following motor nerve lesions.