Auditory Interneurones in the Metathoracic Ganglion of the Grasshopper Chorthippus Biguttulus: I. Morphological and Physiological Characterization

1991 ◽  
Vol 158 (1) ◽  
pp. 391-410 ◽  
Author(s):  
ANDREAS STUMPNER ◽  
BERNHARD RONACHER
Keyword(s):  
White Noise ◽  
Dynamic Range ◽  
Lucifer Yellow ◽  
Physiological Characterization ◽  
Acoustic Stimuli ◽  
Physiological Properties ◽  
Metathoracic Ganglion ◽  
Branching Patterns ◽  
Dependent Inhibition ◽  
Chorthippus Biguttulus

1. Auditory intemeurones originating in the metathoracic ganglion of females of the grasshopper Chorthippus biguttulus can be classified as local (SN), bisegmental (BSN), T-shaped (TN) and ascending neurones (AN). A comparison of branching patterns and physiological properties indicates that auditory interneurones of C. biguttulus are homologous with those described for the locust. 2. Eighteen types of auditory neurones are morphologically characterized on the basis of Lucifer Yellow staining. All of them branch bilaterally in the metathoracic ganglion. Smooth dendrites, from which postsynaptic potentials (PSPs) can be recorded, predominate on the side ipsilateral to the soma. If ‘beaded’ branches exist, they predominate contralaterally. The ascending axon runs contralaterally to the soma, except in T-fibres. 3. Auditory receptors respond tonically. The dynamic range of their intensity-response curve covers 20–25 dB. Local, bisegmental and T-shaped neurones are most sensitive to stimulation ipsilateral to the soma. The responses of SN1 and TNI to white-noise stimuli are similar to those of receptors, while phasic-tonic responses are found in SN4, SN5, SN7 and BSN1. The bisegmental neurones receive side-dependent inhibition that corresponds to a 20–30dB attenuation. One local element (SN6) is predominantly inhibited by acoustic stimuli. 4. Ascending neurones are more sensitive to contralateral stimulation (i.e. on their axon side). Only one of them (AN6) responds tonically to white-noise stimuli at all intensities; others exhibit a tonic discharge only at low or at high intensities.One neurone (AN12) responds with a phasic burst over a wide intensity range. The most directional neurones (AN1, AN2) are excited by contralateral stimuli and (predominantly) inhibited by ipsilateral stimuli. Three ascending neurones (AN13-AN15) are spontaneously active and are inhibited by acoustic stimuli. 5. All auditory intemeurones, except SN5, are more sensitive to pure tones below 10 kHz than to ultrasound.

scholarly journals GABA-like immunoreactivity in nonspiking interneurons of the locust metathoracic ganglion

2002 ◽  
Vol 205 (23) ◽  
pp. 3651-3659 ◽  
Author(s):  
M. Wildman ◽  
S. R. Ott ◽  
M. Burrows
Keyword(s):  
Membrane Potential ◽  
Motor Neurons ◽  
Lucifer Yellow ◽  
Current Injection ◽  
Aminobutyric Acid ◽  
Homogeneous Population ◽  
Metathoracic Ganglion ◽  
Nonspiking Interneurons ◽  
Intracellular Microelectrodes ◽  
Gaba Immunohistochemistry

SUMMARYNonspiking interneurons are important components of the premotor circuitry in the thoracic ganglia of insects. Their action on postsynaptic neurons appears to be predominantly inhibitory, but it is not known which transmitter(s) they use. Here, we demonstrate that many but not all nonspiking local interneurons in the locust metathoracic ganglion are immunopositive for GABA (γ-aminobutyric acid). Interneurons were impaled with intracellular microelectrodes and were shown physiologically to be nonspiking. They were further characterized by defining their effects on known leg motor neurons when their membrane potential was manipulated by current injection. Lucifer Yellow was then injected into these interneurons to reveal their cell bodies and the morphology of their branches. Some could be recognised as individuals by comparison with previous detailed descriptions. Ganglia were then processed for GABA immunohistochemistry. Fifteen of the 17 nonspiking interneurons studied were immunopositive for GABA, but two were not. The results suggest that the majority of these interneurons might exert their well-characterized effects on other neurons through the release of GABA but that some appear to use a transmitter other than GABA. These nonspiking interneurons are therefore not an homogeneous population with regard to their putative transmitter.

Neuroendocrine bag cells of Aplysia are activated by bag cell peptide-containing neurons in the pleural ganglion

1989 ◽  
Vol 61 (6) ◽  
pp. 1142-1152 ◽  
Author(s):  
R. O. Brown ◽  
S. M. Pulst ◽  
E. Mayeri
Keyword(s):  
Lucifer Yellow ◽  
Cell Activity ◽  
Feedback Mechanism ◽  
Egg Laying ◽  
Electrophysiological Properties ◽  
Physiological Properties ◽  
Positive Feedback Mechanism ◽  
Bag Cells ◽  
Small Clusters

1. The generation of egg-laying behavior in the marine mollusk Aplysia involves a prolonged burst discharge in the neuroendocrine bag cells, which secrete neuropeptides derived from the egg-laying hormone/bag cell peptide (ELH/BCP) precursor protein. 2. Besides the bag cells, which are located in the abdominal ganglion, small clusters of neurons in the cerebral and pleural ganglia also express the ELH/BCP neuropeptides. We made intracellular recordings from 32 of these ELH/BCP cells in right pleural ganglia, in 18 preparations, to characterize their physiological properties and their functional relationship to the bag cells. 3. The identification of these ELH/BCP cells was confirmed by pressure injection of Lucifer yellow and subsequent immunocytochemical processing for alpha-BCP immunoreactivity. 4. The basic electrophysiological properties of the pleural ELH/BCP cells were similar to those of the bag cells. These pleural cells were directly demonstrated to be electrically coupled, and direct intracellular stimulation of individual pleural ELH/BCP cells initiated prolonged, synchronous burst discharges in the entire cluster through a positive feedback mechanism. 5. Burst discharges elicited in the pleural ELH/BCP cells consistently initiated burst discharges in the bag cells. Bag cell burst discharges were less effective in initiating burst discharges in the pleural ELH/BCP cells, indicating that there were reciprocal but asymmetrical connections. 6. The results show that the pleural ELH/BCP cells are functionally coupled to the bag cells. They support the hypothesis that the pleural ELH/BCP cells are part of the descending pathway that initiates bag cell activity and egg-laying behavior, in vivo.

scholarly journals Auditory Interneurones in the Metathoracic Ganglion of the Grasshopper Chorthippus Biguttulus: II. Processing of Temporal Patterns of the Song of the Male

1991 ◽  
Vol 158 (1) ◽  
pp. 411-430 ◽  
Author(s):  
ANDREAS STUMPNER ◽  
BERNHARD RONACHER ◽  
OTTO VON HELVERSEN
Keyword(s):  
Response Curve ◽  
Temporal Patterns ◽  
Behavioural Response ◽  
Complete Inhibition ◽  
Similar Response ◽  
Sound Direction ◽  
Intensity Range ◽  
Metathoracic Ganglion ◽  
Chorthippus Biguttulus

1. Auditory interneurones originating in the metathoracic ganglion of females of the grasshopper Chorthippus biguttulus were investigated with respect to their processing of models of the male's song. In these models two temporal configurations were varied: (i) the song pattern, consisting of ‘syllables’ and ‘pauses’, and (ii) the duration of short gaps within syllables. 2. A precise encoding of the song pattern is found only among receptors and ‘thoracic’ neurones (SN1, TNI), but not among ascending neurones. The only ascending neurone that reacts tonically at all intensities (AN6) encodes the song pattern much less precisely than do receptors. Other ascending neurones (AN3, AN11) encode the gross pattern of model songs, but only at low intensities. 3. One spontaneously active ‘local’ neurone (SN6) is tonically inhibited and encodes the pauses of a model song. A similar response, however, is not found in three ascending neurones (AN13, AN14, AN15), which are merely inhibited. 4. Among ascending neurones, AN12 is the most reliably influenced by the syllable-pause structure of the songs. Its phasic burst marks the onset of every syllable in a behaviourally attractive song. Its activity could account for the rising part of the corresponding behavioural response curve. However, no ascending neurone shows activity corresponding to the falling part of the behavioural response. Among local neurones, the phasic BSN1 neurones are most clearly influenced by varying syllable-pause combinations. 5. Gaps within the song syllables cause a complete inhibition of the activity of AN4. The response of AN4 to syllables with and without gaps is strikingly similar to the behavioural response and is maintained over the whole intensity range tested. Several local neurones, especially SN6, are strongly influenced by gaps within model songs - though only in certain intensity ranges. 6. In accordance with behavioural results, the pathways for information on song pattern and sound direction appear to be separated among ascending neurones. Among local interneurones, however, this separation does not appear to take place, since the most directional local neurone, BSN1, might also be suited for pattern-filtering tasks.

scholarly journals Imprinting on time-structured acoustic stimuli in ducklings

2021 ◽  
Vol 17 (9) ◽  
Author(s):  
Tiago Monteiro ◽  
Tom Hart ◽  
Alex Kacelnik
Keyword(s):  
White Noise ◽  
Learning Process ◽  
Anas Platyrhynchos ◽  
Temporal Structure ◽  
Movement Pattern ◽  
Natural Sounds ◽  
Acoustic Stimuli ◽  
Timing Information ◽  
Active Selection ◽  
Filial Imprinting

Filial imprinting is a dedicated learning process that lacks explicit reinforcement. The phenomenon itself is narrowly heritably canalized, but its content, the representation of the parental object, reflects the circumstances of the newborn. Imprinting has recently been shown to be even more subtle and complex than previously envisaged, since ducklings and chicks are now known to select and represent for later generalization abstract conceptual properties of the objects they perceive as neonates, including movement pattern, heterogeneity and inter-component relationships of same or different. Here, we investigate day-old Mallard ( Anas platyrhynchos ) ducklings’ bias towards imprinting on acoustic stimuli made from mallards’ vocalizations as opposed to white noise, whether they imprint on the temporal structure of brief acoustic stimuli of either kind, and whether they generalize timing information across the two sounds. Our data are consistent with a strong innate preference for natural sounds, but do not reliably establish sensitivity to temporal relations. This fits with the view that imprinting includes the establishment of representations of both primary percepts and selective abstract properties of their early perceptual input, meshing together genetically transmitted prior pre-dispositions with active selection and processing of the perceptual input.

scholarly journals Physiological and Pharmacological Studies on Cervical Motor Neurons in Slices Prepared from Neonatal and Aged Mice

2021 ◽  
pp. 1-5
Author(s):  
David O. Carpenter ◽  
N Hori ◽  
Z Xu ◽  
N Akaike ◽  
Y Tan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Motor Neurons ◽  
Excitatory Amino Acid ◽  
Lucifer Yellow ◽  
Membrane Resistance ◽  
Aged Mice ◽  
Lucifer Yellow Ch ◽  
Physiological Properties ◽  
Pharmacological Studies ◽  
Delayed Recovery

The effects of age on the physiological properties of cervical motor neurons were examined in slices made from an excised spinal cord graft of ICR mice from the second day after birth to age 350 days. The membrane potential of post-natal day 2 (PD2) to PD350 was about -65 mV and did not change greatly with age, although it was slightly higher at PD2. However, there were significant changes in membrane resistance, which increased with age from about 15 to 30 MΩ. The depolarization induced by the excitatory amino acid agonists, kainic acid, NMDA and AMPA, decreased with aging in spite of the increase in membrane resistance. The motor neurons of the aged mice showed delayed recovery from excitation caused by excitatory amino acid agonists. By injecting Lucifer yellow CH into motor neurons, it was observed that the dendrite trees become thin, and some of the dendrite branches were missing in older animals.

scholarly journals When complex neuronal structures may not matter

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Adriane G Otopalik ◽  
Alexander C Sutton ◽  
Matthew Banghart ◽  
Eve Marder
Keyword(s):  
Morphological Variability ◽  
Gastric Mill ◽  
Neuron Type ◽  
Recording Site ◽  
Cancer Borealis ◽  
Physiological Properties ◽  
Branching Patterns ◽  
Identified Neuron ◽  
Channel Expression ◽  
Reversal Potentials

Much work has explored animal-to-animal variability and compensation in ion channel expression. Yet, little is known regarding the physiological consequences of morphological variability. We quantify animal-to-animal variability in cable lengths (CV = 0.4) and branching patterns in the Gastric Mill (GM) neuron, an identified neuron type with highly-conserved physiological properties in the crustacean stomatogastric ganglion (STG) of Cancer borealis. We examined passive GM electrotonic structure by measuring the amplitudes and apparent reversal potentials (Erevs) of inhibitory responses evoked with focal glutamate photo-uncaging in the presence of TTX. Apparent Erevs were relatively invariant across sites (mean CV ± SD = 0.04 ± 0.01; 7–20 sites in each of 10 neurons), which ranged between 100–800 µm from the somatic recording site. Thus, GM neurons are remarkably electrotonically compact (estimated λ > 1.5 mm). Electrotonically compact structures, in consort with graded transmission, provide an elegant solution to observed morphological variability in the STG.

Rate-level functions of neurons in the inferior colliculus of cats measured with the use of free-field sound stimuli

1991 ◽  
Vol 65 (2) ◽  
pp. 383-392 ◽  
Author(s):  
L. Aitkin
Keyword(s):  
Firing Rate ◽  
Inferior Colliculus ◽  
Dynamic Range ◽  
Discharge Rate ◽  
Free Field ◽  
Peak Level ◽  
Stimulus Level ◽  
Sound Level ◽  
Acoustic Stimuli ◽  
Rate Level

1. The responses as a function of stimulus level of 125 single units in the inferior colliculus of anesthetized cats were studied with the use of free-field acoustic stimuli. 2. The characteristic frequency (CF; frequency at which threshold was lowest) of each unit was determined, and stimuli were presented from one of three speaker positions: 45 degrees contralateral to the midline, midline, and 45 degrees ipsilateral to the midline. 3. For each unit a variety of stimulus levels was presented at CF, and the total spike count was summed for 20 stimuli at each level. If time permitted, a similar series of levels of noise was presented. 4. Four classes of rate-level (RL) functions were observed. Monotonic increases in firing rate were observed in 10% of units stimulated with CF stimuli and 57% of units studied with noise. Nonmonotonic RL functions, for which firing first increased and then declined to less than 50% of the peak level, were observed in 61% of units responding to CF tones and in 10% responding to noise. Plateau functions, with shapes lying between these, accounted for 19% of CF responses and the remaining units excited by noise. Some very complex shapes that could not be categorized into the above groups were seen in the remaining 10% of the units responding to CF stimuli. 5. The RL functions of units studied with both noise and CF tones could belong to different classes; commonly, nonmonotonic RL functions to tones were associated with monotonic RL functions to noise. The noise thresholds averaged 10 dB, some 10-20 dB less sensitive than those to CF stimuli. 6. For the vast majority of both noise and tone responses, stimuli from the contralateral location were more effective than those from the other two positions in terms of a lower threshold, higher peak discharge rate, and, for nonmonotonic units, a lower sound level at which the function became nonmonotonic (turnover point). 7. The turnover points of nonmonotonic functions at any given CF could be spread broadly but, overall, tended to be concentrated between -6 and 44 dB. 8. The dynamic ranges (range of levels over which firing rate increased) were larger for monotonic and plateau functions than for nonmonotonic functions, which had dynamic ranges less than 45 dB. The median dynamic range for units stimulated with CF tones was 20 dB and for noise stimuli, 40 dB.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparative electrophysiology of pyramidal and sparsely spiny stellate neurons of the neocortex

1985 ◽  
Vol 54 (4) ◽  
pp. 782-806 ◽  
Author(s):  
D. A. McCormick ◽  
B. W. Connors ◽  
J. W. Lighthall ◽  
D. A. Prince
Keyword(s):  
Action Potentials ◽  
Maximum Rate ◽  
Lucifer Yellow ◽  
Cell Types ◽  
Anterior Cingulate ◽  
Electrophysiological Properties ◽  
Physiological Properties ◽  
Fast Spiking ◽  
Tonic Current

Slices of sensorimotor and anterior cingulate cortex from guinea pigs were maintained in vitro and bathed in a normal physiological medium. Electrophysiological properties of neurons were assessed with intracellular recording techniques. Some neurons were identified morphologically by intracellular injection of the fluorescent dye Lucifer yellow CH. Three distinct neuronal classes of electrophysiological behavior were observed; these were termed regular spiking, bursting, and fast spiking. The physiological properties of neurons from sensorimotor and anterior cingulate areas did not differ significantly. Regular-spiking cells were characterized by action potentials with a mean duration of 0.80 ms at one-half amplitude, a ratio of maximum rate of spike rise to maximum rate of fall of 4.12, and a prominent afterhyperpolarization following a train of spikes. The primary slope of initial spike frequency versus injected current intensity was 241 Hz/nA. During prolonged suprathreshold current pulses the frequency of firing adapted strongly. When local synaptic pathways were activated, all cells were transiently excited and then strongly inhibited. Bursting cells were distinguished by their ability to generate endogenous, all-or-none bursts of three to five action potentials. Their properties were otherwise very similar to regular-spiking cells. The ability to generate a burst was eliminated when the membrane was depolarized to near the firing threshold with tonic current. By contrast, hyperpolarization of regular-spiking (i.e., nonbursting) cells did not uncover latent bursting tendencies. The action potentials of fast-spiking cells were much briefer (mean of 0.32 ms) than those of the other cell types.(ABSTRACT TRUNCATED AT 250 WORDS)

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