Related Experiment Video
Updated: Aug 15, 2026
07:04
Physiological, Morphological and Neurochemical Characterization of Neurons Modulated by Movement
Published on: April 21, 2011
Acetylcholine in neurons and paraneurons: a histochemical study
Archives of Histology and Cytology
|January 1, 1989
Summary
This study introduces "ionic fixation," a novel electron microscopy technique for localizing acetylcholine in nerve terminals. The method visualizes acetylcholine in synaptic vesicles and reveals its presence in paraneurons and exocrine cells, highlighting cellular plasticity.
Area of Science:
- Neuroscience
- Cell Biology
- Histochemistry
Background:
- Acetylcholine is a key neurotransmitter in neuronal signaling.
- Limited understanding exists regarding acetylcholine's role in paraneurons and exocrine cells.
- Previous methods for acetylcholine localization were insufficient for detailed ultrastructural analysis.
Purpose of the Study:
- To present and validate a histochemical method for acetylcholine localization using electron microscopy.
- To investigate the presence and distribution of acetylcholine in various cell types, including neurons, paraneurons, and exocrine cells.
- To explore the physiological implications of acetylcholine in non-neuronal cells.
Main Methods:
- Development of
- ionic fixation
- a rapid precipitation technique using heteropolyanions to visualize quaternary ammonium cations.
- Application of the method to motor end-plates, paraneurons, and exocrine secretory cells.
- Electron microscopy for visualizing insoluble acetylcholine precipitates.
Main Results:
- Acetylcholine was localized as distinct precipitates within synaptic vesicles in nerve terminals.
- The method preserved cellular ultrastructure, including membranes.
- Acetylcholine was detected in paraneurons under specific physiological conditions, suggesting cellular plasticity.
- High cholinesterase activity and the presence of acetylcholine were observed in exocrine secretory cells.
Conclusions:
- Ionic fixation
- provides a reliable method for electron microscopic visualization of acetylcholine.
- Acetylcholine plays a role in paraneurons and exocrine cells, indicating broader physiological functions beyond neurotransmission.
- The findings suggest acetylcholine's involvement in cellular metabolism and plasticity in diverse cell types.
More Related Videos
Related Concept Videos
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:30Classification of Neurotransmitters
Neurotransmitters play a crucial role in the communication between neurons in the autonomic nervous system. Neurons in the autonomic nervous system can be cholinergic or adrenergic depending on the neurotransmitters synthesized. Cholinergic neurons use acetylcholine as their primary neurotransmitter. This includes all the preganglionic fibers of the sympathetic and pre- and postganglionic fibers of the parasympathetic nervous systems. In addition, neurons of the somatic nervous system also use...
01:23Cholinergic Neurons: Neurotransmission
Cholinergic neurotransmission involves the synthesis and the release of acetylcholine (ACh) in order to transmit nerve impulses across the synapse. The process begins with the synthesis of acetyl CoA, a precursor for ACh, from ATP, acetate, and coenzyme A in the mitochondria. Choline, another vital precursor, is transported inside the neuron through choline transporters, including high-affinity choline transporter CHT1, low-affinity choline transporter CTL1, and lower-affinity choline...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:30Neurotransmitters
Neurotransmitters play a crucial role in the communication between neurons in the autonomic nervous system. Neurons in the autonomic nervous system can be cholinergic or adrenergic depending on the neurotransmitters synthesized. Cholinergic neurons use acetylcholine as their primary neurotransmitter. This includes all the preganglionic fibers of the sympathetic and pre- and postganglionic fibers of the parasympathetic nervous systems. In addition, neurons of the somatic nervous system also use...
01:30Parasympathetic Signaling
Parasympathetic signaling plays a crucial role in regulating various physiological processes. It involves the release of acetylcholine (ACh) by parasympathetic neurons, which can have localized and short-lived effects. The majority of ACh released is rapidly inactivated at the synapse by the enzyme acetylcholinesterase (AChE), which hydrolyzes Ach into choline and acetate. Additionally, the tissue cholinesterase deactivates any ACh diffusing into the surrounding tissues.
The effects of...
The effects of...