PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 8098853

Rhythmic and patterned neuronal firing in visual cortex.

G L Shaw·J Krüger·D J Silverman·A M Aertsen·F Aiple·H C Liu
View original source ↗Export metadata ↓

Abstract

We present evidence from multi-electrode recordings that the stimulus driven activity in a region of monkey visual cortex displays synchronous, oscillatory behaviour with temporally changing patterns of firing. The spatial-temporal patterns are dependent on cortical layer and on visual stimulus, 'build up and die down' with a period of 70-100 msec, and cannot be factorized into separate spatial and temporal components. This finding supports neural network models which explicitly incorporate spatial-temporal structure, ruling against a purely spatial code for information processing. The new type of analysis presented here is also suitable for direct on-line interactive analysis during multi-electrode recording experiments. Further, it could be modified for use in human EEG or evoked response recordings.

Explore related subjects

Action PotentialsAnimalsCercopithecusCortical SynchronizationMicroelectrodesNerve NetNeuronsPeriodicityVisual CortexJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G L Shaw, J Krüger, D J Silverman, A M Aertsen, F Aiple, H C Liu. 1993. Rhythmic and patterned neuronal firing in visual cortex.. https://doi.org/10.1080/01616412.1993.11740106

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2000

Reconstruction of rat peripheral nerve gap without sutures using freeze-dried alginate gel.

Many materials have been used for artificial tubular prostheses to assist peripheral nerve gap reconstruction. However, the clinical use of these devices has been restricted because a microsurgical procedure requires specialized techniques and expensive equipment, such as operating microscope systems. Therefore the authors developed a new gluing method, without sutures, that uses freeze-dried alginate gel. A 7-mm gap in the sciatic nerve of rats was bridged with freeze-dried alginate gel. Regeneration was evaluated by electrophysiologic testing and histologic study. Eighteen weeks after surgery, functional reinnervation of motor and sensory nerves had occurred, as demonstrated by recovery of compound muscle action potentials (CMAP), compound nerve action potentials (CNAP), and somatosensory-evoked potentials (SEP). Histologically, many regenerated nerve fasciculi, including myelinated and unmyelinated fibers, were observed and the implanted alginate gel had disappeared. In conclusion, a gluing technique using alginate gel is a potential alternative to the conventional nerve autograft technique. Advantages include simple application and rapid repair. Freeze-dried alginate gel is a promising material for artificial nerve guides for peripheral nerves and also could be used for repair of disrupted pathways in central nervous tissue that is amorphous and cannot be sutured.

Action Potentials↗
PubMed2000

Pseudofacilitation: A temperature-sensitive phenomenon.

With sustained isometric exercise, compound muscle action potential (CMAP) amplitude of normal subjects may increase, a phenomenon known as pseudofacilitation. To explore the mechanism of pseudofacilitation, the effect of exercise combined with focal heating and cooling of abductor pollicis brevis was examined in 10 normal subjects. After 10 s of isometric exercise, CMAP amplitude increased by 3.6% (median value) at 32 degrees C and 6.4% at 40 degrees C, and decreased by 9.1% at 20 degrees C. Duration decreased by 12.6% at 32 degrees C and 11.7% at 42 degrees C, but increased by 12.4% at 20 degrees C. Area decreased by 9.8% at 32 degrees C and 8. 6% at 42 degrees C, and increased by 1.1% at 20 degrees C. Changes with cooling were significant (P < 0.01) as compared to baseline (32 degrees C); changes with heating were not. Thus, cooling reverses the expected increase in CMAP amplitude normally seen with exercise. Although providing only indirect evidence, these findings are consistent with the hypothesis that increased activity of muscle Na(+),K(+)-pump plays a role in producing pseudofacilitation.

Action Potentials↗
PubMed2000

Diagnostic criteria for demyelinating polyneuropathy associated with monoclonal gammopathy.

In order to define diagnostic criteria for the demyelinating polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS), we compared 30 patients with idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) without a monoclonal gammopathy, with 29 patients with polyneuropathy associated with MGUS. All 59 patients fulfilled research criteria for CIDP. In the patients with MGUS, sensory symptoms and signs predominated, there was usually no cranial nerve involvement, and the neuropathy was symmetrical with a slowly progressive course. On electrophysiological examination, an abnormal median nerve sensory action potential in combination with a normal sural nerve action potential (AMNS) was not found. In idiopathic CIDP patients, a preceding infection was frequent, motor features predominated, there was often cranial nerve involvement, the neuropathy could be asymmetrical, and AMNS was frequently found. Diagnostic criteria for demyelinating polyneuropathy associated with MGUS are presented.

Action Potentials↗