Related Experiment Video
Updated: Aug 12, 2026

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica
Published on: March 25, 2013
Ultrastructure of the bimodal pacemaker neuron in the central nervous system of Helix pomatia L
Abstract:
Fine structure of the identified (RPal) giant neuron of Helix pomatia has been investigated after isolation. The following findings have been established: 1. The cytoplasm of the RPal neuron is electron-microscopically characterized by a strongly invaginated nuclear envelope, a highly-developed rER system, a large number of free ribosomes and by 110-250 nm-sized neurosecretory-like granules with finely-granulated inner content. 2. The fine-structural arrangement of the cytoplasm exhibited a seasonal variation, viz. in winter it was found to be layered, while in spring it showed a homogeneous structure. 3. On the cell surface free axon profiles containing vesicles were sometimes found, which might be afferent connections to the cell body.
Related Concept Videos
Action Potentials
Action Potential
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Nervous Tissue: Neuron Types
Structurally, neurons are categorized into three main types: multipolar, bipolar, and unipolar (or pseudounipolar). Multipolar neurons, which are the most common type in the brain and spinal cord, as well as all motor neurons, possess multiple dendrites and a single axon.
Bipolar neurons, on the other hand, have one primary dendrite and one axon. They are...
Action Potential
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Neural Circuits
Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that...
Conduction System of the Heart
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...

