Single unit responses of the reticular and ventral anterior nuclei of the thalamus to electrical stimulation of the centrum medianum

1980 ◽  
Vol 12 (1) ◽  
pp. 30-37
Author(s):  
M. Ya. Voloshin ◽  
V. F. Prokopenko
Keyword(s):  
Electrical Stimulation ◽  
Single Unit ◽  
Centrum Medianum ◽  
Stimulation Of

Single Unit Activity in the Inferior Colliculus of the Rat Elicited by Electrical Stimulation of the Cochlea

1997 ◽  
Vol 36 (4) ◽  
pp. 202-227 ◽  
Author(s):  
M. W. Vischer ◽  
V. M. Bajo ◽  
J. S. Zhang ◽  
E. Calciati ◽  
C. A. Haenggeli ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Inferior Colliculus ◽  
Unit Activity ◽  
Single Unit ◽  
Single Unit Activity ◽  
Stimulation Of

scholarly journals An ultrafast system for signaling mechanical pain in human skin

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw1297 ◽  
Author(s):  
Saad S. Nagi ◽  
Andrew G. Marshall ◽  
Adarsh Makdani ◽  
Ewa Jarocka ◽  
Jaquette Liljencrantz ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Human Skin ◽  
Single Unit ◽  
High Threshold ◽  
Mechanical Stimuli ◽  
Loss Of Function ◽  
Conduction Velocities ◽  
Low Threshold ◽  
Healthy Participants ◽  
Stimulation Of

The canonical view is that touch is signaled by fast-conducting, thickly myelinated afferents, whereas pain is signaled by slow-conducting, thinly myelinated (“fast” pain) or unmyelinated (“slow” pain) afferents. While other mammals have thickly myelinated afferents signaling pain (ultrafast nociceptors), these have not been demonstrated in humans. Here, we performed single-unit axonal recordings (microneurography) from cutaneous mechanoreceptive afferents in healthy participants. We identified A-fiber high-threshold mechanoreceptors (A-HTMRs) that were insensitive to gentle touch, encoded noxious skin indentations, and displayed conduction velocities similar to A-fiber low-threshold mechanoreceptors. Intraneural electrical stimulation of single ultrafast A-HTMRs evoked painful percepts. Testing in patients with selective deafferentation revealed impaired pain judgments to graded mechanical stimuli only when thickly myelinated fibers were absent. This function was preserved in patients with a loss-of-function mutation in mechanotransduction channel PIEZO2. These findings demonstrate that human mechanical pain does not require PIEZO2 and can be signaled by fast-conducting, thickly myelinated afferents.

Physiological studies of cutaneous inputs to dorsal horn laminae I-IV of adult chickens

1992 ◽  
Vol 67 (2) ◽  
pp. 241-254 ◽  
Author(s):  
C. J. Woodbury
Keyword(s):  
Electrical Stimulation ◽  
Dorsal Horn ◽  
Single Unit ◽  
Sensory Modality ◽  
Primary Afferent ◽  
C Fibers ◽  
Multiunit Activity ◽  
Natural Stimulation ◽  
Afferent Inputs ◽  
Stimulation Of

1. The dorsal horn (DH) of chickens exhibits a novel pattern of cytoarchitectonic lamination among vertebrates, whereby lamina III lies medial, rather than ventral, to lamina II. Indeed, cutaneous nerves labeled with horseradish peroxidase (HRP) form two separate projections across the mediolateral axis of the superficial DH; each projection is somatotopically organized, such that two non-overlapping somatotopic maps are formed: the medial map within lamina III and the lateral map within lamina II. Interestingly, these two projections of cutaneous nerves are differentially labeled by HRP ligands. The present experiments were designed to address whether the separate subpopulations of cutaneous afferents, as demonstrated neuroanatomically, also differ physiologically on the basis of myelination, fiber diameter, and/or sensory modality. 2. Extracellular multi- and single-unit recordings were obtained in the DH at the ninth synsacral level of spinal adult chickens anesthetized with alpha-chloralose. Activity in lateral (laminae I/II) and medial DH (laminae III/IV) was studied after both electrical stimulation of the caudal femoral cutaneous nerve (CFC) and natural stimulation of the skin. Single units were characterized in terms of the conduction velocity (CV) and sensory modality of their cutaneous afferent inputs. 3. In multiunit recordings, electrical stimulation of the CFC above C-fiber intensities elicited a robust, long-latency response in lateral (laminae I/II) but not medial DH (laminae III/V). The afferents responsible for this late lateral response were C-fibers, as evidenced by a CV of approximately 1 m/s; birds were spinalized to rule out long spinal loops. In contrast, only a single, short-latency (and low-threshold) multiunit response was seen in medial DH, even after activation of C-fibers. 4. Natural stimulation of skin revealed a clear segregation of sensory modalities between medial (laminae III/IV) and lateral DH (laminae I/II). Innocuous mechanical stimuli were extremely effective at eliciting multiunit activity in medial DH, but ineffective in lateral DH. In contrast, noxious mechanical and thermal stimuli were extremely effective at eliciting multiunit activity in lateral DH, but were ineffective in medial DH. 5. In single-unit studies, primary afferent inputs to units in medial DH (laminae III/IV) had an average CV close to 43 m/s; no medial units received exclusive inputs from afferents with CVs less than 5.5 m/s. In contrast, primary afferent inputs to units in lateral DH (laminae I/II) had an average CV close to 10 m/s; 20% of the lateral units received exclusive inputs from C-fibers (CVs less than 1.7 m/s; N = 1.2 m/s).(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document