Topological organization of the trigeminal system in the lamprey and restoration following axonal regeneration
type: CreativeWork
description: The nervous systems of lower vertebrates, such as the lamprey, share many of the basic features of the brain and spinal cord of higher vertebrates. However, unlike humans and other higher vertebrates, the lamprey displays robust axonal regeneration in the central nervous system following neural injuries. For example, following spinal cord transections, the descending axons of brain neurons regenerate and reconnect with spinal targets so that locomotor behavior recovers in a few weeks. The sensory and motor areas of the vertebrate nervous system often exhibit a topological or somatotopic organization, presumably to facilitate efficient transmission and processing of information. Preliminary results suggested the existence of a topological organization of the trigeminal system in the lamprey. The purpose of the current study was two-fold: (1) confirm the topological organization of the trigeminal system in normal animals; and (2) determine if this organization is restored following trigeminal nerve transection. Anatomical double labeling techniques with fluorescent tracers, Alexa 488 and TRDA, were used to confirm the existence of a topological organization in normal and trigeminal-nerve lesioned animals. First, in normal animals, the topological organization of the trigeminal nerve was confirmed. Specifically, Alexa 488 applied to the anteromedial oral hood (anterior head) labeled motoneurons in the medial part of the trigeminal motor nucleus (nVm) and sensory axons in the medial part of the trigeminal descending tracts (dV). In addition, TRDA applied to the anterolateral oral hood labeled trigeminal motoneurons in nVm and sensory axons in dV that were located laterally in these structures. Second, in trigeminal nerve-lesioned animals, the topological organization of the trigeminal system, especially in nVm, was restored. Following trigeminal nerve transection, experimental animals were separated into different recovery groups (4, 8, 12, or 16 weeks), and Alexa 488 a…
abstract: The nervous systems of lower vertebrates, such as the lamprey, share many of the basic features of the brain and spinal cord of higher vertebrates. However, unlike humans and other higher vertebrates, the lamprey displays robust axonal regeneration in the central nervous system following neural injuries. For example, following spinal cord transections, the descending axons of brain neurons regenerate and reconnect with spinal targets so that locomotor behavior recovers in a few weeks. The sensory and motor areas of the vertebrate nervous system often exhibit a topological or somatotopic organization, presumably to facilitate efficient transmission and processing of information. Preliminary results suggested the existence of a topological organization of the trigeminal system in the lamprey. The purpose of the current study was two-fold: (1) confirm the topological organization of the trigeminal system in normal animals; and (2) determine if this organization is restored following trigeminal nerve transection. Anatomical double labeling techniques with fluorescent tracers, Alexa 488 and TRDA, were used to confirm the existence of a topological organization in normal and trigeminal-nerve lesioned animals. First, in normal animals, the topological organization of the trigeminal nerve was confirmed. Specifically, Alexa 488 applied to the anteromedial oral hood (anterior head) labeled motoneurons in the medial part of the trigeminal motor nucleus (nVm) and sensory axons in the medial part of the trigeminal descending tracts (dV). In addition, TRDA applied to the anterolateral oral hood labeled trigeminal motoneurons in nVm and sensory axons in dV that were located laterally in these structures. Second, in trigeminal nerve-lesioned animals, the topological organization of the trigeminal system, especially in nVm, was restored. Following trigeminal nerve transection, experimental animals were separated into different recovery groups (4, 8, 12, or 16 weeks), and Alexa 488 a…
author: Ly, Lexie ToLoan
language: eng
language: English
date published: 2012
date modified: 2026-07-24T03:07:24Z
provider: University of Missouri
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Missouri--Columbia

PropertyValue
property ID: Handle
value: http://hdl.handle.net/10355/43352