Network interactions among sensory neurons in the leech

Burgin, Antonia Marín; Szczupak, Lidia

doi:10.1007/s00359-002-0377-8

Cited by 15 publications

(29 citation statements)

References 14 publications

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“…Two types of mechanical stimulation of the skin were applied: "localized bubbling" and "localized stream." The localized bubbling method was previously described (Marín Burgin and Szczupak 2003). Briefly, air pressure pulses were delivered through a micropipette, which had a tip of around 5 m, by a Picospritzer II pressure-pulse generator (General Valve, Fairfield, NJ) on the skin.…”

Section: Skin Stimulation and Video Recordingmentioning

confidence: 99%

“…Experiments were performed using body wall preparations (see METHODS) where the skin was stimulated by localized bubbling of the external solution (Marín Burgin and Szczupak 2003), and T and AE cells were recorded by means of intracellular electrodes. Stimulation of the appropriate sensory field (Lewis and Kristan 1998;Marín Burgin and Szczupak 2003;Nicholls and Baylor 1968) evoked a series of action potentials in the recorded T cell throughout the stimulus period (Fig. 1Ai).…”

Section: Effect Of Ae Activity On the Responsiveness Of T Cells To Mementioning

confidence: 99%

“…The higher-threshold mechanosensory neurons (P and N cells) do not respond to this type of stimulation (Marín Burgin and Szczupak 2003). That the T cells could be the primary sensory detectors of the applied stimuli is suggested by the fact that they respond when the whole preparation is bathed in a solution containing a high Mg 2ϩ /Ca 2ϩ ratio, which precludes any chemical synaptic interaction (Marín Burgin and Szczupak 2003).…”

Section: Effect Of Ae Activity On the Responsiveness Of T Cells To Mementioning

confidence: 99%

“…In a previous study, we showed that T cells are activated by the light touch produced by air bubbling onto the skin (Marín Burgin and Szczupak 2003), and in this study, we show that these low-threshold mechanosensory neurons were also excited by flow of water parallel to the surface of the skin, as first demonstrated by Nicholls and Baylor (1968). It was suggested that water motion evoked T cell activity through excitatory synaptic input from sensillar water movement receptors (SMRs), rather than by direct stimulation of its terminals (Friesen 1981).…”

Section: Mechanosensory Signals In the Leechmentioning

confidence: 99%

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Modulation of Mechanosensory Responses by Motoneurons That Regulate Skin Surface Topology in the Leech

Rodriguez

Iscla

Szczupak

2004

Journal of Neurophysiology

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Central regulation of somatosensory signals has been extensively studied, but little is known about their regulation in the periphery. Given the widespread exposure of the skin sensory terminals to the environment, it is of interest to explore how somatosensory sensitivity is affected by changes in properties of the skin. In the leech, the annuli that subdivide the skin can be erected under the control of the annulus erector (AE) motoneurons. To analyze whether this surface change influences mechanosensory sensitivity, we studied the responses of low threshold mechanosensory T cells to mechanical stimulation of the skin as AE motoneurons were activated. In segments of the body wall connected to the corresponding ganglion and submerged in an aqueous environment, T cells responded to localized bubbling on the skin and to water flow parallel to its surface. Excitation of AE motoneurons diminished these responses in a way that depended on the motoneuron firing frequency. Video recordings established that the range of AE firing frequencies that produced effective annulus erection coincided with that influencing T cell responses. In isolated ganglia, AE firing had no effect on T cell excitability, suggesting that annulus erection diminished T cell responsiveness to mechanical input. Counteracting this effect, mechanosensory inputs inhibited AE motoneurons. However, because depolarization of AE cells caused a decrease in their input resistance, the more active the motoneuron, the less sensitive it became to inhibitory signals. Thus when brought to fire, AE motoneurons would stay "committed" to a high activity level, and this would limit sensory responsiveness to incoming mechanical signals.

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Section: Skin Stimulation and Video Recordingmentioning

confidence: 99%

Section: Effect Of Ae Activity On the Responsiveness Of T Cells To Mementioning

confidence: 99%

Section: Effect Of Ae Activity On the Responsiveness Of T Cells To Mementioning

confidence: 99%

Section: Mechanosensory Signals In the Leechmentioning

confidence: 99%

See 2 more Smart Citations

Modulation of Mechanosensory Responses by Motoneurons That Regulate Skin Surface Topology in the Leech

Rodriguez

Iscla

Szczupak

2004

Journal of Neurophysiology

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“…Mechano-sensory cells in leech are directly linked to mechanical transduction at the skin surface, as quenching synaptic transmission does not suppress mechano-sensory signaling in these neurons ( Burgin and Szczupak, 2003 ; Nicholls and Baylor, 1968 ). Thus, mechano-sensory transduction is supposed to drive N, T and P cells directly.…”

Section: Resultsmentioning

confidence: 99%

Intrinsic frequency response patterns in mechano-sensory neurons of the leech

Fischer¹,

Scherbarth²,

Chagnaud

et al. 2017

Biology Open

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Animals employ mechano-sensory systems to detect and explore their environment. Mechano-sensation encompasses stimuli such as constant pressure, surface movement or vibrations at various intensities that need to be segregated in the central nervous system. Besides different receptor structures, sensory filtering via intrinsic response properties could provide a convenient way to solve this problem. In leech, three major mechano-sensory cell types can be distinguished, according to their stimulus sensitivity, as nociceptive, pressure and touch cells. Using intracellular recordings, we show that the different mechano-sensory neuron classes in Hirudo medicinalis differentially respond supra-threshold to distinct frequencies of sinusoidal current injections between 0.2 and 20 Hz. Nociceptive cells responded with a low-pass filter characteristic, pressure cells as high-pass filters and touch cells as an intermediate band-pass filter. Each class of mechano-sensory neurons is thus intrinsically tuned to a specific frequency range of voltage oscillation that could help segregate mechano-sensory information centrally.

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Spatial-specific action of serotonin within the leech midbody ganglion

Calviño

Szczupak

2008

J Comp Physiol A

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Serotonin is a conspicuous neuromodulator in the nervous system of many vertebrates and invertebrates. In previous experiments performed in the leech nervous system, we compared the effect of the amine released from endogenous sources [using selective serotonin reuptake inhibitors (SSRIs), e.g. fluoxetine] with that of bath-applied serotonin. The results suggested that the amine does not reach all its targets in a uniform way, but produces the activation of an interneuronal pathway that generated specific synaptic responses on different neurons. Taking into account that the release of the amine is often regulated at the presynaptic level, we have investigated whether autoreceptor antagonists mimic the SSRIs effect. We found that methiothepin (100 microM) produced similar effects than fluoxetine. To further test the hypothesis that endogenous serotonin produce its effect by acting locally at specific sites, we analyzed the effect of iontophoretic applications of serotonin. We found a site in the neuropil of the leech ganglia where serotonin application mimicked the effect of the SSRIs and the 5-HT antagonist. The results further support the view that the effect of serotonin exhibits a spatial specificity that can be relevant to understand its modulatory actions.

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Network interactions among sensory neurons in the leech

Cited by 15 publications

References 14 publications

Modulation of Mechanosensory Responses by Motoneurons That Regulate Skin Surface Topology in the Leech

Modulation of Mechanosensory Responses by Motoneurons That Regulate Skin Surface Topology in the Leech

Intrinsic frequency response patterns in mechano-sensory neurons of the leech

Spatial-specific action of serotonin within the leech midbody ganglion

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