Neuronal control of leech behavior

  title={Neuronal control of leech behavior},
  author={William B. Kristan and Ronald L. Calabrese and W. Otto Friesen},
  journal={Progress in Neurobiology},

A classic model animal in the 21st century: recent lessons from the leech nervous system

Robust behaviors and a simple and accessible nervous system made the leech a favorite among systems neuroscientists, and increasing use of modern techniques helps explain its continued appeal.

Neural circuits controlling behavior and autonomic functions in medicinal leeches

Some of the best understood movements of medicinal leeches and the circuits which underlie them are discussed, focusing on swimming, crawling and heartbeat.

Mechanisms of behavioral choice in the nervous system of the medicinal leech

This work uses the leech as a model system to explore how animals place different priorities on different behaviors due to its simple nervous system, its readily identifiable neurons, and its amenability to reduced preparations, and believes that distributed decision-making networks may be universal in the nervous systems of all complex animals.

Spontaneous Electrical Activity and Behavior in the Leech Hirudo Medicinalis

Large bursts of spikes occurring spontaneously were recorded and caused the leech to move even in the absence of any external sensory stimulation and appear to act as internal triggers controlling the spontaneous leech behavior and determining the duration of stereotypical motor patterns.

Functions of the subesophageal ganglion in the medicinal leech revealed by ablation of neuromeres in embryos

Although the midbody ganglia of the leech CNS display a high degree of local autonomy, the cephalic brain is a source of selective inhibition that modulates behaviour, integrates sensory information from the head with signals from the rest of the body, and plays an important role in organizing at least some complicated whole-body behaviours.

The stomatogastric nervous system of the medicinal leech: its anatomy, physiology and associated aminergic neurons

The presence and characteristics of the stomatogastric nervous system, vital for feeding, are reported here for the first time and provide a new foundation for understanding the regulation and modulation of neural networks involved in feeding.

Dopamine Induces Rhythmic Activity and Enhances Postinhibitory Rebound in a Leech Motor Neuron Involved in Swimming and Crawling Behaviors

Bath application of dopamine to isolated leech ganglia induces rhythmic oscillatory activity in cell DE-3, consistent with crawling, but not swimming behavior, which provides further support for the hypothesis that dopamine promotes crawling behavior in the leech.

Specialized brain regions and sensory inputs that control locomotion in leeches

It is suggested that the supraesophageal ganglion is the primary structure that constrains leech swimming; however, the control of swim duration in the leech is complex, especially in the intact animal.



Development of spontaneous and evoked behaviors in the medicinal leech

The order in which behaviors arise during the period of embryonic development is investigated and the time at which each behavior is first expressed is determined, finding that in response to stimulation of the midbody, young embryos produced a behavior called “circumferential indentation,” whereas older embryos produced local bending, a response previously described for adults.

Neuronal control of leech swimming.

The pathway by which body wall stimulation initiates swimming shows a simple form of learning, that is habituation, and the biogenic amine serotonin, which is found in the nerve cord, affects leech swimming in a number of ways.

Serotonin in the leech central nervous system: anatomical correlates and behavioral effects

Morphometric analyses indicated that ganglionic levels of serotonin correlated primarily with longitudinal variations in the number of serotonin neurons per ganglion and secondarily with volume of the Retzius cells, both of which are largest in mid-body domains.

The neurobiology of swimming in the leech

  • W. Kristan
  • Biology, Psychology
    Trends in Neurosciences
  • 1983

Modulation of swimming behavior in the medicinal leech

It is proposed that alterations in synaptic interactions resulting from exposure to elevated serotonin levels, coupled with the changes in MN cellular properties described earlier, are crucial to the increased efficacy of MNs in participating in generating and expressing the leech swimming rhythm.

A cephalic projection neuron involved in locomotion is dye coupled to the dopaminergic neural network in the medicinal leech

It is demonstrated that Tr2 is dye coupled to the dopaminergic neural network distributed in the head brain, and it is determined that bath application of DA to the brain and entire nerve cord reliably and rapidly terminates swimming in all preparations exhibiting fictive swimming.

The neural control of alternate heartbeat coordination states in the leech,Hirudo medicinalis

A more complete heart control circuit diagram is now available that accounts for the observed activity cycles of the various HN and HE cells and consequently for the behavior of the hearts themselves.

Physiological and morphological analysis of synaptic transmission between leech motor neurons

Three different methods were used to demonstrate that synaptic transmission remained in the absence of impulses in the inhibitory motor neurons, and it is proposed that these inhibitory connections between motor neurons are probably monosynaptic.

Serotonin integrates the feeding behavior of the medicinal leech

Serotonin is localized to a limited population of identifiable neurons in the C.N.S., and plays a pivotal and mandatory role in organizing the feeding behavior of the medicinal leech.