Related Experiment Videos
Substance P and hydra: an immunohistochemical and physiological study
P Pierobon1, M Kemali, N Milici
1Istituto Cibernetica C.N.R., Napoli, Italy.
Summary
Substance P, a neuropeptide, is found in Hydra attenuata nerve cells and developing nematoblasts. While not affecting regeneration, it triggers tentacle contractions and nematocyst discharge, suggesting a role in contractile functions.
Area of Science:
- Neurobiology
- Invertebrate physiology
- Cell biology
Background:
- Substance P is a well-known neuropeptide in vertebrate nervous systems.
- Its presence and function in simpler organisms like Hydra are less understood.
- Hydra possess a diffuse nerve net, making them a model for studying basic neurobiology.
Purpose of the Study:
- To investigate the distribution of substance P-like immunoreactivity in Hydra attenuata.
- To determine the functional effects of exogenous substance P on Hydra.
- To explore the potential role of substance P in Hydra physiology.
Main Methods:
- Immunohistochemistry using the peroxidase-antiperoxidase technique to visualize substance P.
- Administration of synthetic substance P to regenerating Hydra specimens.
- Observation of regeneration rates, tentacle contraction, and nematocyst behavior.
Main Results:
- Substance P-like immunoreactivity was detected in ectodermal nerve cells, fibers, and developing nematoblasts.
- Exogenous substance P did not alter the rate of Hydra regeneration.
- Synthetic substance P induced tentacle contraction and nematocyst displacement within battery cells.
Conclusions:
- Substance P-like molecules are present in the nervous system and developing cells of Hydra.
- Substance P appears to influence contractile processes in Hydra tissues, such as tentacle movement.
- These findings suggest a conserved role for substance P in contractile functions across different species.