Physiology and Plasticity of Morphologically Identified Cells in the Mormyrid Electrosensory Lobe

Bell, Charles E.; Caputi, Ángel A.; Grant, Kirsty

doi:10.1523/jneurosci.17-16-06409.1997

Cited by 83 publications

(108 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cartwheel cells have NMDA receptors, whereas Purkinje cells do not (36). The DCN closely resembles electrosensory lobes of fishes where principal cells and Purkinje-cell homologues receive parallel fiber input and have NMDA receptors (7,37,38).…”

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

Bidirectional synaptic plasticity in the cerebellum-like mammalian dorsal cochlear nucleus

Fujino

Oertel

2002

Proc. Natl. Acad. Sci. U.S.A.

116

133

View full text Add to dashboard Cite

The dorsal cochlear nucleus integrates acoustic with multimodal sensory inputs from widespread areas of the brain. Multimodal inputs are brought to spiny dendrites of fusiform and cartwheel cells in the molecular layer by parallel fibers through synapses that are subject to long-term potentiation and long-term depression. Acoustic cues are brought to smooth dendrites of fusiform cells in the deep layer by auditory nerve fibers through synapses that do not show plasticity. Plasticity requires Ca 2؉ -induced Ca 2؉ release; its sensitivity to antagonists of N-methyl-D-aspartate and metabotropic glutamate receptors differs in fusiform and cartwheel cells.A uditory nerve fibers bring acoustic information to the cochlear nucleus and feed it into several parallel pathways that ascend through the brainstem. Pathways through the dorsal cochlear nucleus (DCN) are thought to detect spectral cues for localizing sounds monaurally (1). Those through the ventral cochlear nucleus (VCN) encode spectral and temporal characteristics that allow sounds to be localized in the horizontal plane, through binaural circuits, and recognized.The DCN resembles the cerebellum, cartwheel cells being homologues of cerebellar Purkinje cells (2). Fusiform cells project to the inferior colliculus. Granule cells in the vicinity of the cochlear nuclei are innervated by diverse regions of the brain, including the dorsal column nuclei (1), vestibular periphery (3), and auditory nuclei (4, 5). Their unmyelinated axons, parallel fibers, contact spiny dendrites of fusiform and cartwheel cells. Myelinated auditory nerve fibers contact smooth basal dendrites of fusiform cells. The DCN resembles the electrosensory lobes in fishes even more closely (6, 7).In cerebellar circuits, the gain of one of two converging systems of inputs varies as a function of activity. Long-term depression (LTD) at parallel fiber synapses in cerebellar Purkinje cells evoked by coincident excitation through parallel fiber and climbing fiber synapses plays a role in coordination and motor learning (8). Long-term potentiation (LTP) and LTD at parallel fiber synapses are evoked in electric fishes by convergent excitation by parallel fibers and sensory afferents to compensate for an animal's own signals in localizing external sources (9). We show that principal cells of the DCN combine multimodal inputs through parallel fibers whose strength is modulated by activity with invariant acoustic input through auditory nerve fibers. MethodsCoronal slices (200 m) containing the DCN were prepared from ICR mice (Harlan-Sprague-Dawley) between 18 and 20 days old with an oscillating tissue slicer (VT1000S, Leica Microsystems, Nussloch, Germany). Slices were held in a 300-l chamber that was superfused at 3-5 ml͞min with oxygenated saline at Ϸ33°C. Experiments were done in accordance with the protocols and guidelines of the Animal Care and Use Committee at the University of Wisconsin, Madison.Whole-cell patch-clamp recordings were generally made with 3-to 5-M⍀ pipettes filled with a K-gluconate-base...

show abstract

Section: Discussionmentioning

confidence: 98%

“…Blocking mGluRs, presumably a major source of IP 3 , does not block LTD in cartwheel cells. In the electric fish, pairing of the stimulation of parallel fibers with postsynaptic depolarization or with broad action potentials produces both LTP and LTD in homologues of cartwheel and fusiform cells (9,37).…”

Section: Discussionmentioning

confidence: 99%

Bidirectional synaptic plasticity in the cerebellum-like mammalian dorsal cochlear nucleus

Fujino

Oertel

2002

Proc. Natl. Acad. Sci. U.S.A.

116

133

View full text Add to dashboard Cite

show abstract

“…The objectevoked excitation pattern within both ELL zones is processed jointly with an efference copy of the EOD, termed electric organ corollary discharge (EOCD) (Bell, 1989). The EOCD is modifiable by previous sensory experience, such as stimuli in the absence of an object (Bell, 1989;Bell et al, 1997). The circuitry is thus sufficient to provide the modulations caused by the object-evoked peripheral stimulus profile from the fish skin.…”

Section: Spatial Profiles Of Amplitude and Waveform Imagesmentioning

confidence: 99%

Estimation of distance and electric impedance of capacitive objects in the weakly electric fish,Gnathonemus petersii

Gottwald

Bott

Emde

2017

Journal of Experimental Biology

View full text Add to dashboard Cite

During active electrolocation, the weakly electric fish Gnathonemus petersii judges the distance and impedance of nearby objects. Capacitive objects, which modulate local amplitude and waveform of the fish's electric probing signals, cast amplitude and waveform images onto the fish's electroreceptive skin. For an unambiguous estimation of the impedance and distance of an object, the animal has to deal with multiple dependencies of object and image parameters. Based on experimentally recorded amplitude and waveform images, we investigated possible strategies of the fish to unequivocally determine both the distance and the impedance of capacitive objects. We show that the relative slope in amplitude images, but not in waveform images, is independent of object impedance and is a measure of object distance. Distance-invariant impedance estimators were obtained by two different analytical strategies. The peak modulations of both image types were 'calibrated' with the relative slope of the amplitude image. Impedance estimators were obtained whenever these pairs of image features ( peak and relative slope) were related dynamically over two consecutive distances. A static impedance estimator termed 'electric colour' is postulated to arise from the relationship of an amplitude and waveform image. Our results confirm that electric colour is indeed unaffected by object distance. For electric colour estimation we suggest a minimalistic approach of just relating the peak modulations of both image types to the basal amplitude and waveform condition. Our results are discussed with regard to the anatomical and physiological organization of the fish's electrosensory neuronal pathways and behavioural strategies of electrolocating fish.

show abstract

“…ELL neurons integrate precisely timed afferent input with precisely timed electric organ corollary discharge (EOCD) input linked to the motor command to discharge the electric organ (Bell, 1990a;Bell et al, 1997), and behavioral experiments show that fish can detect changes in the relative timing of afferent and EOCD signals as small as 0.1 ms (Hall et al, 1995). The simplicity and precision of the temporal code, as well as the accessibility of central mechanisms for reading the code, make the mormyrid electrosensory system an excellent one for examining the general issue of how nervous systems might use sensory information encoded in precise spike times.…”

Section: Introductionmentioning

confidence: 99%

Effects of Sensing Behavior on a Latency Code

Sawtell¹,

Williams²,

Roberts³

et al. 2006

J. Neurosci.

View full text Add to dashboard Cite

Sensory information is often acquired through active exploration, yet relatively little is known about how neurons encode sensory stimuli in the context of natural patterns of sensing behavior. We examined the effects of sensing behavior on a spike latency code in the active electrosensory system of mormyrid fish. These fish actively probe their environment by emitting brief electric organ discharge (EOD) pulses. Nearby objects alter the spatial pattern of current flowing through the skin. These changes are encoded by small shifts in the latency of individual electroreceptor afferent spikes after the EOD. In nature, the temporal pattern of EOD intervals is highly structured and varies depending on the behavioral context. We performed experiments in which we varied both the EOD amplitude and the intervals between EODs to understand how sensing behavior affects afferent latency coding. We use white-noise stimuli and linear filter estimation methods to develop simple models characterizing the dependence of afferent spike latency on the preceding sequence of EOD intervals and amplitudes. Comparing the predictions of these models with actual afferent responses for natural patterns of EOD intervals and amplitudes reveals an unexpectedly rich interplay between sensing behavior and stimulus encoding. Implications of our results for how afferent spike latency is decoded at central stages of electrosensory processing are discussed.

show abstract

Physiology and Plasticity of Morphologically Identified Cells in the Mormyrid Electrosensory Lobe

Cited by 83 publications

References 31 publications

Bidirectional synaptic plasticity in the cerebellum-like mammalian dorsal cochlear nucleus

Bidirectional synaptic plasticity in the cerebellum-like mammalian dorsal cochlear nucleus

Estimation of distance and electric impedance of capacitive objects in the weakly electric fish,Gnathonemus petersii

Effects of Sensing Behavior on a Latency Code

Contact Info

Product

Resources

About