scholarly journals A novel major output target for pheromone-sensitive projection neurons in male moths

2019 ◽  
Author(s):  
Xi Chu ◽  
Stanley Heinze ◽  
Elena Ian ◽  
Bente G. Berg
Keyword(s):  
Small Region ◽  
Projection Neurons ◽  
Signal Identification ◽  
Odor Quality ◽  
Plant Odors ◽  
Physiological Properties ◽  
Output Neurons ◽  
Male Specific ◽  
Fast Control ◽  
Lateral Tract

AbstractThe male-specific macroglomerular complex (MGC) in the moth antennal lobe contains circuitry dedicated to pheromone processing. Output neurons from this region project along three parallel pathways, the medial, mediolateral, and lateral tracts. The MGC-neurons of the lateral tract are least described and their functional significance is unknown. We used mass-staining, calcium imaging, and intracellular recording/staining to characterize the morphological and physiological properties of these neurons in Helicoverpa armigera. All lateral-tract MGC neurons targeted the column, a small region within the superior intermediate neuropil. We identified this region as the major converging site for lateral-tract neurons responsive to pheromones and plant-odors. The lateral-tract MGC-neurons consistently responded with a faster onset than the well-described medial-tract neurons. Different from the medial-tract MGC neurons encoding odor quality important for signal identification, those in the lateral tract seem to convey a robust and rapid, but fixed signal – potentially important for fast control of hard-wired behavior.

scholarly journals Neurotransmitters in the Mammalian Striatum: Neuronal Circuits and Heterogeneity

1987 ◽  
Vol 14 (S3) ◽  
pp. 386-394 ◽  
Author(s):  
K. Semba ◽  
H.C. Fibiger ◽  
S.R. Vincent
Keyword(s):  
Substantia Nigra ◽  
Aminobutyric Acid ◽  
Projection Neurons ◽  
Medium Spiny Neurons ◽  
Synaptic Connections ◽  
Spiny Neurons ◽  
Striatal Projection Neurons ◽  
Matrix Organization ◽  
Output Neurons ◽  
Striatal Interneurons

ABSTRACT:The major input and output pathways of the mammalian striatum have been well established. Recent studies have identified a number of neurotransmitters used by these pathways as well as by striatal interneurons, and have begun to unravel their synaptic connections. The major output neurons have been identified as medium spiny neurons which contain ɣ-aminobutyric acid (GABA), endogeneous opioids, and substance P. These neurons project to the pallidum and substantia nigra in a topographic and probably chemically organized manner. The major striatal afferents from the cerebral cortex, thalamus, and substantia nigra terminate, at least in part, on these striatal projection neurons. Striatal interneurons contain acetylcholine, GABA, and somatostatin plus neuropeptide Y, and appear to synapse on striatal projection neurons. In recent years, much activity has been directed to the neurochemical and hodological heterogeneities which occur at a macroscopic level in the striatum. This has led to the concept of a patch-matrix organization in the striatum.

scholarly journals Pauses in cholinergic interneuron firing exert an inhibitory control on striatal output in vivo

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Stefano Zucca ◽  
Aya Zucca ◽  
Takashi Nakano ◽  
Sho Aoki ◽  
Jeffery Wickens
Keyword(s):  
Membrane Potential ◽  
Projection Neurons ◽  
Tonic Firing ◽  
Short Term Plasticity ◽  
Cholinergic Interneurons ◽  
Significant Events ◽  
Output Neurons ◽  
Potential Activity ◽  
Membrane Potential Fluctuations

The cholinergic interneurons (CINs) of the striatum are crucial for normal motor and behavioral functions of the basal ganglia. Striatal CINs exhibit tonic firing punctuated by distinct pauses. Pauses occur in response to motivationally significant events, but their function is unknown. Here we investigated the effects of pauses in CIN firing on spiny projection neurons (SPNs) – the output neurons of the striatum – using in vivo whole cell and juxtacellular recordings in mice. We found that optogenetically-induced pauses in CIN firing inhibited subthreshold membrane potential activity and decreased firing of SPNs. During pauses, SPN membrane potential fluctuations became more hyperpolarized and UP state durations became shorter. In addition, short-term plasticity of corticostriatal inputs was decreased during pauses. Our results indicate that, in vivo, the net effect of the pause in CIN firing on SPNs activity is inhibition and provide a novel mechanism for cholinergic control of striatal output.

Microstimulation of the primate neostriatum. I. Physiological properties of striatal microexcitable zones

1985 ◽  
Vol 53 (6) ◽  
pp. 1401-1416 ◽  
Author(s):  
G. E. Alexander ◽  
M. R. DeLong
Keyword(s):  
Motor Response ◽  
Internal Capsule ◽  
Ibotenic Acid ◽  
Body Parts ◽  
Antidromic Activation ◽  
Orofacial Movements ◽  
Stimulus Current ◽  
Physiological Properties ◽  
Current Spread ◽  
Output Neurons

Microstimulation was carried out at over 1,250 sites in the putamen in four unanesthetized rhesus monkeys. At numerous sites, microstimulation resulted in movements of individual body parts including leg, arm, and face. Microstimulation-evoked limb movements were invariably contralateral to the stimulating electrode. In nearly all instances, the response at threshold was restricted to or maximal about a single joint. A small percentage of stimulation-evoked axial and orofacial movements were bilateral. The same motor response was frequently evoked over distances of up to 1,200 micron along a single penetration, suggesting that a relatively homogeneous motor-response zone underlies the observed micro-stimulation effects. We have designated these presumptive functional units striatal microexcitable zones (SMZ). The boundaries of adjacent SMZ involved in different movements frequently appeared to overlap. Amplitude, velocity, and acceleration of microstimulation-evoked elbow movements were assessed quantitatively. With increasing stimulus current, each of these parameters increased monotonically until saturation occurred. The spread of intrastriatal microstimulation currents was found to be comparable to that reported for motor cortex. The effective radius of 40-microA putamen microstimulation currents was estimated to be approximately 150 micron. This effectively rules out the possibility of current spread to the internal capsule. Microstimulation effects were abolished by fiber-sparing lesions produced by microinjections of the neurotoxin ibotenic acid. Moreover, chronaxie measurements in putamen (327 +/- 47 microseconds) were significantly higher than for capsular stimulation (150 +/- 32 microseconds). These observations are consistent with the proposal that movements evoked by putamen microstimulation resulted from activation of putamen output neurons. On the other hand, a possible contribution from the antidromic activation of corticostriate afferent terminals or axons cannot be excluded.

Olfactory interneurons in the moth Manduca sexta : response characteristics and morphology of central neurons in the antennal lobes

1981 ◽  
Vol 213 (1192) ◽  
pp. 249-277 ◽  
Keyword(s):  
Manduca Sexta ◽  
Sensory Information ◽  
Single Type ◽  
Antennal Lobes ◽  
Response Characteristics ◽  
Male Moth ◽  
Central Neurons ◽  
Local Interneurons ◽  
Output Neurons ◽  
Male Specific

The antennal lobes of the moth Manduca sexta are composed of two distinct classes of central neurons: local interneurons, involved in sensory processing within the lobe, and output neurons, the relay elements carrying sensory information to higher neuropil centres in the brain. The different types of neurons in each class share many characteristics. All of the local interneurons have extensive multiglomerular dendritic arborizations and lack distinct axons while all of the output neurons have uniglomerular dendritic arborizations. In addition to these general characteristics the central neurons of the antennal lobes also possess a distinct sexual dimorphism. Only the male moth responds to the female sex pheromone. All of the central neurons in the antennal lobe of the male moth th at respond to pheromone have dendritic branches located in the macroglomerular complex, a male-specific neuropil region. Two types of pheromone-sensitive local interneurons have been described morphologically and physiologically while a single type of output neuron has been found that has a dendritic arborization in the macroglomerular complex.

scholarly journals Semi-intact ex vivo approach to investigate spinal somatosensory circuits

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Junichi Hachisuka ◽  
Kyle M Baumbauer ◽  
Yu Omori ◽  
Lindsey M Snyder ◽  
H Richard Koerber ◽  
...  
Keyword(s):  
Neural Circuits ◽  
Ex Vivo ◽  
Projection Neurons ◽  
New Approach ◽  
Spinal Interneurons ◽  
Somatosensory Input ◽  
Health And Disease ◽  
Output Neurons ◽  
Temporal And Spatial ◽  
Ex Vivo Approach

The somatosensory input that gives rise to the perceptions of pain, itch, cold and heat are initially integrated in the superficial dorsal horn of the spinal cord. Here, we describe a new approach to investigate these neural circuits in mouse. This semi-intact somatosensory preparation enables recording from spinal output neurons, while precisely controlling somatosensory input, and simultaneously manipulating specific populations of spinal interneurons. Our findings suggest that spinal interneurons show distinct temporal and spatial tuning properties. We also show that modality selectivity — mechanical, heat and cold — can be assessed in both retrogradely labeled spinoparabrachial projection neurons and genetically labeled spinal interneurons. Finally, we demonstrate that interneuron connectivity can be determined via optogenetic activation of specific interneuron subtypes. This new approach may facilitate key conceptual advances in our understanding of the spinal somatosensory circuits in health and disease.

scholarly journals Morphology, PKCδ expression, and synaptic responsiveness of different types of rat central lateral amygdala neurons

2012 ◽  
Vol 108 (12) ◽  
pp. 3196-3205 ◽  
Author(s):  
Taiju Amano ◽  
Alon Amir ◽  
Sonal Goswami ◽  
Denis Paré
Keyword(s):  
Fear Conditioning ◽  
Conditioned Fear ◽  
Morphological Properties ◽  
Lateral Amygdala ◽  
Postsynaptic Potentials ◽  
Physiological Properties ◽  
Major Species ◽  
Low Threshold ◽  
Output Neurons ◽  
Dendritic Branches

Recent findings implicate the central lateral amygdala (CeL) in conditioned fear. Indeed, CeL contains neurons exhibiting positive (CeL-On) or negative (CeL-Off) responses to fear-inducing conditioned stimuli (CSs). In mice, these cells differ in their expression of protein kinase Cδ (PKCδ) and physiological properties. CeL-Off cells are PKCδ+ and late firing (LF), whereas CeL-On cells are PKCδ− and express a regular-spiking (RS) or low-threshold bursting (LTB) phenotype. However, the scarcity of LF cells in rats raises questions about the correspondence between the organization of CeL in mice and rats. Therefore, we studied the PKCδ expression, morphological properties, synaptic responsiveness, and fear conditioning-induced plasticity of rat CeL neurons. No PKCδ+ LF cells were encountered, but ≈20–25% of RS and LTB neurons were PKCδ+. Compared with RS neurons, a higher proportion of LTB cells projected to central medial amygdala (CeM) and they had fewer primary dendritic branches, yet the amplitude of excitatory postsynaptic potentials (EPSPs) evoked by lateral amygdala (LA) stimulation was similar in RS and LTB cells. In contrast, LA-evoked inhibitory postsynaptic potentials (IPSPs) had a higher amplitude in LTB than RS neurons. Finally, fear conditioning did not induce plasticity at LA inputs to RS or LTB neurons. These findings point to major species differences in the organization of CeL. Since rat LTB cells are subjected to stronger feedforward inhibition, they are more likely to exhibit inhibitory CS responses than RS cells. This is expected to cause a disinhibition of CeM fear output neurons and therefore an increase in fear expression.

Mushroom Body of the Honeybee

2017 ◽  
pp. 353-360
Author(s):  
Jürgen Rybak ◽  
Randolf Menzel
Keyword(s):  
Mushroom Body ◽  
Higher Order ◽  
Insect Species ◽  
Insect Brain ◽  
Projection Neurons ◽  
Kenyon Cells ◽  
Output Neurons ◽  
The Brain

The mushroom body (MB) in the insect brain is composed of a large number of densely packed neurons called Kenyon cells (KCs) (Drosophila, 2200; honeybee, 170,000). In most insect species, the MB consists of two caplike dorsal structures, the calyces, which contain the dendrites of KCs, and two to four lobes formed by collaterals of branching KC axons. Although the MB receives input and provides output throughout its whole structure, the neuropil part of the calyx receives predominantly multimodal input from sensory projection neurons (PNs) of second or a higher order, and the lobes send output neurons to many other parts of the brain, including recurrent neurons to the MB calyx. Widely branching, supposedly modulatory neurons (serotonergic, octopaminergic) innervate the MB at all levels (calyx, peduncle, and lobes), including the somata of KCs in the calyx (dopamine).

scholarly journals Muscarinic acetylcholine receptor signaling generates OFF selectivity in a simple visual circuit

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Bo Qin ◽  
Tim-Henning Humberg ◽  
Anna Kim ◽  
Hyong S. Kim ◽  
Jacob Short ◽  
...  
Keyword(s):  
Acetylcholine Receptor ◽  
Visual Processing ◽  
Muscarinic Acetylcholine Receptor ◽  
Projection Neurons ◽  
Visually Guided ◽  
Genetic Studies ◽  
Muscarinic Acetylcholine ◽  
Cholinergic Signaling ◽  
Physiological Properties ◽  
Sign Inversion

Abstract ON and OFF selectivity in visual processing is encoded by parallel pathways that respond to either light increments or decrements. Despite lacking the anatomical features to support split channels, Drosophila larvae effectively perform visually-guided behaviors. To understand principles guiding visual computation in this simple circuit, we focus on investigating the physiological properties and behavioral relevance of larval visual interneurons. We find that the ON vs. OFF discrimination in the larval visual circuit emerges through light-elicited cholinergic signaling that depolarizes a cholinergic interneuron (cha-lOLP) and hyperpolarizes a glutamatergic interneuron (glu-lOLP). Genetic studies further indicate that muscarinic acetylcholine receptor (mAchR)/Gαo signaling produces the sign-inversion required for OFF detection in glu-lOLP, the disruption of which strongly impacts both physiological responses of downstream projection neurons and dark-induced pausing behavior. Together, our studies identify the molecular and circuit mechanisms underlying ON vs. OFF discrimination in the Drosophila larval visual system.

scholarly journals Kv3-Like Potassium Channels Are Required for Sustained High-Frequency Firing in Basal Ganglia Output Neurons

2011 ◽  
Vol 105 (2) ◽  
pp. 554-570 ◽  
Author(s):  
Shengyuan Ding ◽  
Shannon G. Matta ◽  
Fu-Ming Zhou
Keyword(s):  
Basal Ganglia ◽  
High Frequency ◽  
Movement Control ◽  
Dopamine Neurons ◽  
Pcr Analysis ◽  
Delayed Rectifier ◽  
Projection Neurons ◽  
Gaba Neurons ◽  
Fast Spiking ◽  
Output Neurons

The GABA projection neurons in the substantial nigra pars reticulata (SNr) are key output neurons of the basal ganglia motor control circuit. These neurons fire sustained high-frequency, short-duration spikes that provide a tonic inhibition to their targets and are critical to movement control. We hypothesized that a robust voltage-activated K+ conductance that activates quickly and resists inactivation is essential to the remarkable fast-spiking capability in these neurons. Semi-quantitative RT-PCR (qRT-PCR) analysis on laser capture-microdissected nigral neurons indicated that mRNAs for Kv3.1 and Kv3.4, two key subunits for forming high activation threshold, fast-activating, slow-inactivating, 1 mM tetraethylammonium (TEA)-sensitive, fast delayed rectifier ( IDR-fast) type Kv channels, are more abundant in fast-spiking SNr GABA neurons than in slow-spiking nigral dopamine neurons. Nucleated patch clamp recordings showed that SNr GABA neurons have a strong Kv3-like IDR-fast current sensitive to 1 mM TEA that activates quickly at depolarized membrane potentials and is resistant to inactivation. IDR-fast is smaller in nigral dopamine neurons. Pharmacological blockade of IDR-fast by 1 mM TEA impaired the high-frequency firing capability in SNr GABA neurons. Taken together, these results indicate that Kv3-like channels mediating fast-activating, inactivation-resistant IDR-fast current are critical to the sustained high-frequency firing in SNr GABA projection neurons and hence movement control.

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