PubMed Health⌕ Search

PubMed · 16383660

Block structured dynamics and neuronal coding.

Abstract

When certain control parameters of nervous cell models are varied, complex bifurcation structures develop in which the dynamical behaviors available appear classified in blocks, according to criteria of dynamical likelihood. This block structured dynamics may be a clue to understand how activated neurons encode information by firing spike trains of their action potentials.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J M González-Miranda. 2005-11-18. Block structured dynamics and neuronal coding.. https://doi.org/10.1103/physreve.72.051922

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

KEEP EXPLORING

Related citations

Prostaglandin E2 potentiates the excitability of small diameter trigeminal root ganglion neurons projecting onto the superficial layer of the cervical dorsal horn in rats.

The aim of the present study was to investigate how prostaglandin E2 (PGE2) affects the excitability of trigeminal root ganglion (TRG) neurons, projecting onto the superficial layer of the cervical dorsal horn, using fluorescence retrograde tracing and perforated patch-clamp techniques. TRG neurons were retrogradely labeled with fluorogold (FG). The cell diameter of FG-labeled neurons was small (< 30 microm). Under the voltage-clamp mode, application of PGE2 (0.01-10 microM) concentration-dependently increased the magnitude of the peak tetrodotoxin-resistant sodium current (TTX-R I(Na)) and this current was maximal at a concentration of 1 microM. One micromolar PGE2 application caused a hyperpolarizing shift of 8.3 mV in the activation curve for TTX-R I(Na). In the current-clamp mode, the PGE2 (1 microM) application significantly increased the number of action potentials during the depolarizing step pulses as well as the level of overshoot but had no significant effect on the resting membrane potential. These results suggest that the excitability of small diameter TRG neurons seen after 1 microM PGE2 application is involved in an increase in the

Action Potentials↗

Case report: the split flexor carpi ulnaris as a local muscle flap.

The flexor carpi ulnaris is a useful local muscle flap in the forearm and elbow. It is, however, an important palmar flexor and ulnar deviator of the wrist, and functional loss may arise from the use of this muscle in its entirety. The flexor carpi ulnaris is made up of two distinct neuromuscular compartments. This arrangement allows for splitting of the muscle and the potential use of the larger ulnar compartment as a local muscle flap while maintaining the humeral compartment as an ulnar deviator and palmar flexor of the wrist. We report two cases illustrating the clinical use of the split flexor carpi ulnaris as a local muscle flap.

Action Potentials↗

Physiological and morphological characterization of parvalbumin-containing interneurons of the rat basolateral amygdala.

The basolateral amygdala (BLA) is critical for the generation of emotional behavior and the formation of emotional memory. Understanding the neuronal mechanisms that contribute to emotional information processing in the BLA will ultimately require knowledge of the anatomy and physiology of its constituent neurons. Two major cell classes exist in the BLA, pyramidal projection neurons and nonpyramidal interneurons. Although the properties of projection neurons have been studied in detail, little is known about the properties of BLA interneurons. We have used whole-cell patch clamp recording techniques to examine the physiological properties of 48 visually identified putative interneurons from the rat anterior basolateral amygdalar nucleus. Here, we report that BLA interneurons can be differentiated into four electrophysiologically distinct subtypes based on their intrinsic membrane properties and their response to afferent synaptic input. Interneuron subtypes were named according to their characteristic firing pattern generated in response to transient depolarizing current injection and were grouped as follows: 1) burst-firing interneurons (n = 13), 2) regular-firing interneurons (n = 11), 3) fast-firing interneurons (n = 10), and 4) stutter-firing interneurons (n = 14). Post hoc histochemical visualization confirmed that all 48 recorded neurons had morphological properties consistent with their being local circuit interneurons. Moreover, by using triple immunofluorescence (for biocytin, calcium-binding proteins, and neuropeptides) in conjunction with patch clamp recording, we further demonstrated that over 60% of burst-firing and stutter-firing interneurons also expressed the calcium-binding protein parvalbumin (PV(+)). These data demonstrate that interneurons of the BLA show both physiological and neurochemical diversity. Moreover, we demonstrate that the burst- and stutter-firing patterns positively correlate with PV(+) immunoreactivity, suggesting that these neurons may represent functionally distinct subpopulations.

Action Potentials↗