scholarly journals Mechanosensory Lateral Line Nerve Projections to Auditory Neurons in the Dorsal Descending Octaval Nucleus in the Goldfish, Carassius auratus

2016 ◽  
Vol 88 (1) ◽  
pp. 68-80 ◽  
Author(s):  
Catherine A. McCormick ◽  
Shannon Gallagher ◽  
Evan Cantu-Hertzler ◽  
Scarlet Woodrick
Keyword(s):  
Lateral Line ◽  
Low Frequency ◽  
Cell Types ◽  
Auditory Pathway ◽  
Projection Neurons ◽  
Specific Cell ◽  
Lateral Line Nerve ◽  
First Order ◽  
Goldfish Carassius Auratus ◽  
Auditory Nucleus

The nucleus medialis is the main first-order target of the mechanosensory lateral line (LL) system. This report definitively demonstrates that mechanosensory LL inputs also terminate in the ipsilateral dorsal portion of the descending octaval nucleus (dDO) in the goldfish. The dDO, which is the main first-order auditory nucleus in bony fishes, includes neurons that receive direct input from the otolithic end organs of the inner ear and project to the auditory midbrain. There are two groups of such auditory projection neurons: medial and lateral. The medial and the lateral groups in turn contain several neuronal populations, each of which includes one or more morphological cell types. In goldfish, the exclusively mechanosensory anterior and posterior LL nerves terminate only on specific cell types of auditory projection neurons in the lateral dDO group. Single neurons in the lateral dDO group may receive input from both anterior and posterior LL nerves. It is possible that some of the lateral dDO neurons that receive LL input also receive input from one or more of the otolithic end organs. These results are consistent with functional studies demonstrating low frequency acoustic sensitivity of the mechanosensory LL in teleosts, and they reveal that the anatomical substrate for sensory integration of otolithic and LL inputs is present at the origin of the central ascending auditory pathway in an otophysine fish.

Vertebrate retinal ganglion cells are selected from competent progenitors by the action of Notch

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3637-3650 ◽  
Author(s):  
C.P. Austin ◽  
D.E. Feldman ◽  
J.A. Ida ◽  
C.L. Cepko
Keyword(s):  
Cell Fate ◽  
Ganglion Cells ◽  
Notch Pathway ◽  
Cell Types ◽  
Projection Neurons ◽  
Specific Cell ◽  
Vitro Assay ◽  
Notch Activity

The first cells generated during development of the vertebrate retina are the ganglion cells, the projection neurons of the retina. Although they are one of the most intensively studied cell types within the central nervous system, little is known of the mechanisms that determine ganglion cell fate. We demonstrate that ganglion cells are selected from a large group of competent progenitors that comprise the majority of the early embryonic retina and that differentiation within this group is regulated by Notch. Notch activity in vivo was diminished using antisense oligonucleotides or augmented using a retrovirally transduced constitutively active allele of Notch. The number of ganglion cells produced was inversely related to the level of Notch activity. In addition, the Notch ligand Delta inhibited retinal progenitors from differentiating as ganglion cells to the same degree as did activated Notch in an in vitro assay. These results suggest a conserved strategy for neurogenesis in the retina and describe a versatile in vitro and in vivo system with which to examine the action of the Notch pathway in a specific cell fate decision in a vertebrate.

scholarly journals Single-cell genomics identifies cell type–specific molecular changes in autism

Science ◽  
2019 ◽  
Vol 364 (6441) ◽  
pp. 685-689 ◽  
Author(s):  
Dmitry Velmeshev ◽  
Lucas Schirmer ◽  
Diane Jung ◽  
Maximilian Haeussler ◽  
Yonatan Perez ◽  
...  
Keyword(s):  
Cell Types ◽  
Molecular State ◽  
Clinical Severity ◽  
Projection Neurons ◽  
Specific Cell ◽  
Cortical Projection ◽  
Molecular Changes ◽  
Single Nucleus ◽  
Gene Expression Studies ◽  
Transcriptomic Changes

Despite the clinical and genetic heterogeneity of autism, bulk gene expression studies show that changes in the neocortex of autism patients converge on common genes and pathways. However, direct assessment of specific cell types in the brain affected by autism has not been feasible until recently. We used single-nucleus RNA sequencing of cortical tissue from patients with autism to identify autism-associated transcriptomic changes in specific cell types. We found that synaptic signaling of upper-layer excitatory neurons and the molecular state of microglia are preferentially affected in autism. Moreover, our results show that dysregulation of specific groups of genes in cortico-cortical projection neurons correlates with clinical severity of autism. These findings suggest that molecular changes in upper-layer cortical circuits are linked to behavioral manifestations of autism.

Immunocytochemical Evidence for Electrical Synapses in the Dorsal Descending and Dorsal Anterior Octaval Nuclei in the Goldfish, Carassius auratus

2019 ◽  
Vol 93 (1) ◽  
pp. 34-50
Author(s):  
Catherine A. McCormick
Keyword(s):  
Carassius Auratus ◽  
Axon Terminal ◽  
Vestibular Nuclei ◽  
Auditory Midbrain ◽  
Electrical Synapses ◽  
First Order ◽  
Neuronal Populations ◽  
Goldfish Carassius Auratus ◽  
Dorsal Portion ◽  
Auditory Nucleus

The dorsal portion of the descending octaval nucleus (dDO), the main first-order auditory nucleus in jawed fish, includes four lateral and three medial neuronal populations that project to the auditory midbrain. One medial population and one lateral population contain neurons that receive a remarkably large axon terminal from the utricular branch of the octaval nerve. Immunocytochemistry for connexin 35 (Cx35) was used to determine whether this connection includes electrical synapses. Although Cx35 was not localized to these large contacts, it was observed in the three other lateral dDO populations. Another first-order nucleus, the dorsal portion of the anterior octaval nucleus (dAO), primitively projects to the auditory midbrain in jawed fishes and contains neurons positive for Cx35. Utricular branch terminals were coincident with some Cx35 puncta in dDO and dAO. The results are discussed in light of what is known about the occurrence of electrical synapses in first-order auditory and vestibular nuclei in fish and tetrapods.

scholarly journals Selective and Reversible Blocking of the Lateral Line in Freshwater Fish

1987 ◽  
Vol 133 (1) ◽  
pp. 249-262 ◽  
Author(s):  
HANS ERIK KARLSEN ◽  
OLAV SAND
Keyword(s):  
Inner Ear ◽  
Lateral Line ◽  
Near Field ◽  
Low Frequency ◽  
Rutilus Rutilus ◽  
Directional Hearing ◽  
Roach Rutilus Rutilus ◽  
Cobalt Ions ◽  
Lateral Line Nerve ◽  
Pharmacological Method

Fish possess two separate systems for detection of low-level sound and water motions in the low-frequency range: the inner ear and the lateral line. The relative roles of these systems in normal fish behaviour is still not clear. There is, for instance, a lack of experimental evidence showing the involvement of the lateral line and the inner ear in detection of infrasound, in directional hearing in the near field, and in detection and attack of swimming prey below the surface. To provide a useful tool for such studies, we have developed a pharmacological method for selective and reversible blocking of the lateral line in the roach (Rutilus rutilus). By recording multi-unit activity from the lateral line nerve and microphonic potentials from the inner ear, we have shown that cobalt ions in the external water may completely block the mechanosensitivity of the lateral line without affecting the utricular microphonic activity. This inhibiting effect of Co2+ is antagonized by Ca2+, making the ratio between these ions the important blocking factor. For practical work, we recommend 12–24h exposure to 0.1 mmol 1−1 Co2+ at a Ca2+ concentration of less than 0.1 mmol 1−1. The fish showed no sign of general behavioural disorders even after 1 week in this solution, and the microphonic sensitivity of the inner ear was not reduced. The blocking effect of Co2+ was clearly reversible, and the recovery was dependent upon both the duration of the Co2+ exposure and the Ca2+ concentration of the recovery solution.

Velocity- and acceleration-sensitive units in the trunk lateral line of the trout

1992 ◽  
Vol 68 (6) ◽  
pp. 2212-2221 ◽  
Author(s):  
A. B. Kroese ◽  
N. A. Schellart
Keyword(s):  
Frequency Response ◽  
Spontaneous Activity ◽  
Lateral Line ◽  
Low Frequency ◽  
Water Velocity ◽  
The Other ◽  
Lateral Line Nerve ◽  
Phase Lead ◽  
Afferent Fibers ◽  
Frequency Phase

1. The two main types of lateral line organs of lower vertebrates are the superficial neuromasts (SN), with a cupula that protrudes in the surrounding water, and the canal neuromasts (CN), located in the lateral line canal. The scales of the trunk lateral line canal of fish contain SNs as well as CNs. In this study, we examine whether there exist two functional classes of afferent fibers in the trunk lateral line nerve of the rainbow trout that can be attributed to the SNs and CNs. 2. The response properties of the afferent fibers in the trunk lateral line nerve have been determined during stimulation with sinusoidally varying water motion generated by a small vibrating sphere. Linear frequency response analysis revealed the presence of two distinct populations of afferent fibers in the lateral line nerve. The fibers belonging to the two populations showed significant differences in the frequency at which the sensitivity was maximal, the low-frequency response slope and the low-frequency asymptotic phase angle. 3. One population of fibers has a maximum sensitivity at 36 +/- 13 (SD) Hz (n = 22) and responds up to this frequency to water velocity. The low-frequency slope of the frequency response of these fibers was 20 +/- 3 (SD) dB/decade and the low-frequency phase lead was 121 +/- 11 degrees (mean +/- SD), both with respect to sphere displacement. The fibers of the other population have a maximum sensitivity at 93 +/- 14 (SD) Hz (n = 12) and respond up to this frequency to water acceleration. The low-frequency slope of these fibers was 35 +/- 5 (SD) dB/decade, and the low-frequency phase lead was 188 +/- 13 degrees (mean +/- SD). 4. Analysis of the stochastic properties of the spontaneous activity of both types of fibers revealed that the mean firing rate of the fibers responding to water velocity (26 +/- 12 spikes/s, mean +/- SD; n = 22) was significantly higher than that of the fibers responding to acceleration (36 +/- 11 spikes/s, mean +/- SD; n = 12). The other statistical properties of the spontaneous activity were found to be indistinguishable. 5. From comparison of the results with the available quantitative data on frequency responses of lateral line organs in other species, it has been concluded that the fibers responding (< or = 40 Hz) to water velocity innervate SNs and that the fibers responding (< or = 90 Hz) to water acceleration innervate CNs.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of Sublethal DDT on the Lateral Line of Brook Trout, Salvelinus fontinalis

1968 ◽  
Vol 25 (12) ◽  
pp. 2677-2682 ◽  
Author(s):  
John M. Anderson
Keyword(s):  
Temperature Coefficient ◽  
Lateral Line ◽  
High Frequency ◽  
Brook Trout ◽  
Negative Temperature Coefficient ◽  
Low Frequency ◽  
Negative Temperature ◽  
Lateral Line Nerve ◽  
General Terms ◽  
Frequency Burst

The lateral line nerve of brook trout responds to an abrupt low-frequency pressure wave, generated by a falling drop of water hitting the water surface, by a relatively short high-frequency burst of large spikes. The burst duration has a negative temperature coefficient. Exposure of trout for 24 hr to DDT, ranging from 0.1 to 0.3 ppm, renders the lateral line nerve hypersensitive to the experimental stimulus; in particular there is a marked increase, especially at the colder temperatures, in the negativity of the temperature coefficient of the burst durations. The results are discussed in general terms, as well as specifically in relation to other laboratory work which shows that sublethal DDT affects behavioural responses of fish to temperature.

scholarly journals Hippocampal and thalamic afferents form distinct synaptic microcircuits in the mouse frontal cortex

2021 ◽  
Author(s):  
Kourtney Graham ◽  
Nelson Spruston ◽  
Erik B. Bloss
Keyword(s):  
Information Processing ◽  
Frontal Cortex ◽  
Cortical Neurons ◽  
Basolateral Amygdala ◽  
Cell Types ◽  
Brain Regions ◽  
Projection Neurons ◽  
Specific Cell ◽  
Nucleus Reuniens ◽  
Level Information

AbstractNeural circuits within the frontal cortex support the flexible selection of goal-directed behaviors by integrating input from brain regions associated with sensory, emotional, episodic, and semantic memory functions. From a connectomics perspective, determining how these disparate afferent inputs target their synapses to specific cell types in the frontal cortex may prove crucial in understanding circuit-level information processing. Here, we used monosynaptic retrograde rabies mapping to examine the distribution of afferent neurons targeting four distinct classes of local inhibitory interneurons and four distinct classes of excitatory projection neurons in mouse infralimbic cortex. Interneurons expressing parvalbumin, somatostatin, or vasoactive intestinal peptide received a large proportion of inputs from hippocampal regions, while interneurons expressing neuron-derived neurotrophic factor received a large proportion of inputs from thalamic regions. A more moderate hippocampal-thalamic dichotomy was found among the inputs targeting excitatory neurons that project to the basolateral amygdala, lateral entorhinal cortex, nucleus reuniens of the thalamus, and the periaqueductal gray. Together, these results show a prominent bias among hippocampal and thalamic afferent systems in their targeting to genetically or anatomically defined sets of frontal cortical neurons. Moreover, they suggest the presence of two distinct local microcircuits that control how different inputs govern frontal cortical information processing.

scholarly journals Sex and Pubertal Status Influence Dendritic Spine Density on Frontal Corticostriatal Projection Neurons in Mice

2020 ◽  
Vol 30 (6) ◽  
pp. 3543-3557 ◽  
Author(s):  
Kristen Delevich ◽  
Nana J Okada ◽  
Ameet Rahane ◽  
Zicheng Zhang ◽  
Christopher D Hall ◽  
...  
Keyword(s):  
Adolescent Development ◽  
Dendritic Spine ◽  
Cell Types ◽  
Projection Neurons ◽  
Specific Cell ◽  
Spine Density ◽  
Adult Males ◽  
Puberty Onset ◽  
Spatial Topography ◽  
Spine Pruning

Abstract In humans, nonhuman primates, and rodents, the frontal cortices exhibit grey matter thinning and dendritic spine pruning that extends into adolescence. This maturation is believed to support higher cognition but may also confer psychiatric vulnerability during adolescence. Currently, little is known about how specific cell types in the frontal cortex mature or whether puberty plays a role in the maturation of some cell types but not others. Here, we used mice to characterize the spatial topography and adolescent development of cross-corticostriatal (cSTR) neurons that project through the corpus collosum to the dorsomedial striatum. We found that apical spine density on cSTR neurons in the medial prefrontal cortex decreased significantly between late juvenile (P29) and young adult time points (P60), with females exhibiting higher spine density than males at both ages. Adult males castrated prior to puberty onset had higher spine density compared to sham controls. Adult females ovariectomized before puberty onset showed greater variance in spine density measures on cSTR cells compared to controls, but their mean spine density did not significantly differ from sham controls. Our findings reveal that these cSTR neurons, a subtype of the broader class of intratelencephalic-type neurons, exhibit significant sex differences and suggest that spine pruning on cSTR neurons is regulated by puberty in male mice.

scholarly journals Cell-Type-Specific D1 Dopamine Receptor Modulation of Projection Neurons and Interneurons in the Prefrontal Cortex

2018 ◽  
Vol 29 (7) ◽  
pp. 3224-3242 ◽  
Author(s):  
Paul G Anastasiades ◽  
Christina Boada ◽  
Adam G Carter
Keyword(s):  
Prefrontal Cortex ◽  
Pyramidal Cells ◽  
Cell Types ◽  
D1 Receptor ◽  
Receptor Expression ◽  
D1 Receptors ◽  
Projection Neurons ◽  
Specific Cell ◽  
Action Potential Firing ◽  
Receptor Modulation

Abstract Dopamine modulation in the prefrontal cortex (PFC) mediates diverse effects on neuronal physiology and function, but the expression of dopamine receptors at subpopulations of projection neurons and interneurons remains unresolved. Here, we examine D1 receptor expression and modulation at specific cell types and layers in the mouse prelimbic PFC. We first show that D1 receptors are enriched in pyramidal cells in both layers 5 and 6, and that these cells project to intratelencephalic targets including contralateral cortex, striatum, and claustrum rather than to extratelencephalic structures. We then find that D1 receptors are also present in interneurons and enriched in superficial layer VIP-positive (VIP+) interneurons that coexpresses calretinin but absent from parvalbumin-positive (PV+) and somatostatin-positive (SOM+) interneurons. Finally, we determine that D1 receptors strongly and selectively enhance action potential firing in only a subset of these corticocortical neurons and VIP+ interneurons. Our findings define several novel subpopulations of D1+ neurons, highlighting how modulation via D1 receptors can influence both excitatory and disinhibitory microcircuits in the PFC.

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