The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Alan Gelperin - One of the best experts on this subject based on the ideXlab platform.

  • DOI 10.1007/s10827-006-8097-7 A neuronal network for the logic of Limax learning
    2014
    Co-Authors: Comput J Neurosci, Pranay Goel, Alan Gelperin
    Abstract:

    Abstract We construct a neuronal network to model the logic of associative conditioning as revealed in experimental results using the terrestrial mollusk Limax Maximus. We show, in particular, how blocking to a previously conditioned stimulus in the presence of the unconditional stimulus, can emerge as a dynamical property of the network. We also propose experiments to test the new model

  • A neuronal network for the logic of Limax learning
    Journal of Computational Neuroscience, 2006
    Co-Authors: Pranay Goel, Alan Gelperin
    Abstract:

    We construct a neuronal network to model the logic of associative conditioning as revealed in experimental results using the terrestrial mollusk Limax Maximus. We show, in particular, how blocking to a previously conditioned stimulus in the presence of the unconditional stimulus, can emerge as a dynamical property of the network. We also propose experiments to test the new model.

  • Initiation and Propagation of Calcium-Dependent Action Potentials in a Coupled Network of Olfactory Interneurons
    Journal of neurophysiology, 2001
    Co-Authors: Jing W. Wang, Jorge Flores, Winfried Denk, Alan Gelperin
    Abstract:

    Coherent oscillatory electrical activity and apical-basal wave propagation have been described previously in the procerebral (PC) lobe, an olfactory center of the terrestrial slug Limax Maximus. In...

  • Cultured olfactory interneurons from Limax Maximus: optical and electrophysiological studies of transmitter-evoked responses
    Journal of neurophysiology, 1993
    Co-Authors: Laurence D. Rhines, P. G. Sokolove, Jorge Flores, David W. Tank, Alan Gelperin
    Abstract:

    1. The olfactory processing network in the procerebral (PC) lobe of the terrestrial mollusk Limax Maximus exhibits a coherent oscillation of local field potential that is modulated by odor input. To understand the cellular basis of this oscillation, we developed a cell culture preparation of isolated PC neurons and studied the responses of isolated cells to stimulation with neurotransmitters known to be present in the PC lobe. 2. The distribution of PC soma diameters suggests at least two different populations of neurons. Approximately 95% of isolated cells had soma diameters of 7-8 microns, with the remaining cells having larger diameters (10-15 microns). 3. Extracellular measurements of action potentials and optical measurements of intracellular calcium concentrations in fura-2-loaded cells were made. Serotonin and dopamine excited PC neurons and promoted transitions from steady to bursty activity. Both amines elicited increases in intracellular calcium, presumably concomitant with the increase in action-potential frequency. 4. Glutamate suppressed action-potential firing and reduced intracellular calcium. This effect was seen most clearly when glutamate was applied to cells excited by high potassium medium. Quisqualate is an effective glutamate agonist in this system, whereas kainate is not. 5. Combined with anatomic and biochemical data and with studies of the effects of these neurotransmitters on the oscillating local field potential of the intact PC network, the data from isolated PC neurons are consistent with the hypothesis that dopamine and serotonin modulate network dynamics, whereas glutamate is involved in generating the basic oscillation of local field potential in the PC. 6. The optical studies of fura-2-loaded cells showed that several treatments that increase the rate of action-potential production lead to elevations in intracellular calcium. Optical studies of intracellular calcium may be useful for multisite measurements of activity in the intact, oscillating PC lobe network.

  • Odors can induce feeding motor responses in the terrestrial mollusc Limax Maximus.
    Behavioral neuroscience, 1992
    Co-Authors: Christie L. Sahley, K. A. Martin, Alan Gelperin
    Abstract:

    Highly developed odor learning was shown in the terrestrial slug Limax Maximus. In addition, several key cellular elements of the neural network that controls ingestive feeding have been identified. The results of 3 experiments demonstrate an interaction between odor input and ingestive feeding in that olfactory stimulation with behaviorally attractive odors summed with tactile stimulation from plain agar to produce ingestion of plain agar. Agar ingestion did not occur in the absence of attractive odor stimulation. The adequacy of odor stimulation to trigger agar ingestion was altered by associative learning. Innately attractive odors rendered repellent by associative learning no longer triggered agar ingestion, whereas innately repellent odors rendered attractive by conditioning triggered agar ingestion. The newly discovered feeding command cells in the Limax cerebral ganglion are a logical cellular locus for this interaction.

Anja Taubert - One of the best experts on this subject based on the ideXlab platform.

David J. Prior - One of the best experts on this subject based on the ideXlab platform.

  • Morphological correlate of regional partitioning of integumental water absorption in terrestrial slugs
    Tissue & cell, 1994
    Co-Authors: David J. Prior, Tim Maugel, Marilee Sellers
    Abstract:

    Abstract An ultrastructural study of the foot surface of the terrestrial mollusc, Limax Maximus , has revealed a correlation of epithelial cell type with the functional partitioning of the surface. The lateral absorptive bands of the foot are comprised exclusively of microvillar epithelial cells, while those of the medial locomotor band are all ciliated. Thus, there is a clear partitioning of epithelial cell types between areas of the foot surface with distinct functional roles. Consistent with the proposed role for paracellular absorption, varying states of hydration are shown to affect the extent of the intercellular spaces, but not the intracellular architecture.

  • Modulation of heart activity in the terrestrial slug Limax Maximus by the feeding motor program, small cardioactive peptides and stimulation of buccal neuron B1.
    The Journal of experimental biology, 1991
    Co-Authors: Ian G. Welsford, David J. Prior
    Abstract:

    Activation of the feeding motor program (FMP) increases the force of ventricular contractions in heart/central nervous system (CNS) preparations of the terrestrial slug Limax Maximus (Linnaeus). The FMP-induced increase in ventricular activity requires innervation of the heart by abdominal ganglion nerves N9 and N11. Application of the small cardioactive peptides SCPA and SCPB to isolated preparations of the heart causes dose-dependent increases in the force of ventricular contractions. In addition, the SCPs induce rhythmic contractions in quiescent heart preparations. The effects of the SCPs appear to be specific in that the neuropeptide FMRFamide has an inhibitory effect on ventricular activity. SCP-like and FMRFamide-like immunoreactive material is found in the heart, kidney and pericardium and in the nerves that innervate these organs. Unilateral intracellular stimulation of buccal neuron B1, which contains SCP-like and FMRFamide-like immunoreactive material, mimics the FMP- and SCP-induced increases in ventricular activity. The effect of B1 on ventricular activity is frequency dependent and requires innervation of the heart by N11. These results are consistent with the hypothesis that the SCPs are involved in feeding-related alterations in heart activity in Limax and that the control of this effect involves neuron B1.

  • Control of Central and Peripheral Targets by a Multifunctional Peptidergic Interneuron
    The Biological bulletin, 1991
    Co-Authors: David J. Prior
    Abstract:

    In the terrestrial slug, Limax Maximus, feeding activity and cardiovascular function have been shown to be correlated. For example, in intact animals, both feeding responsiveness and heart activity are suppressed during dehydration (Grega and Prior, 1986). The paired peptidergic buccal ganglion neurons RB1 and LB1 have dramatic modulatory effects on both the feeding motor program (FMP) and the force of heart contraction (Welsford and Prior, 1991). The B1 neurons appear to contain the small cardioactive peptides (SCPs). Observations have a frequency dependent excitation of both the FMP and the heart demonstrated by intracellular stimulation of B1. Thus, interneuron B1 may serve to mediate the coincident modulation of multiple responses to physiological stresses.

Malin K. Lange - One of the best experts on this subject based on the ideXlab platform.

Felipe Penagos-tabares - One of the best experts on this subject based on the ideXlab platform.