scholarly journals Reversing anterior insular cortex neuronal hypoexcitability attenuates compulsive behavior in juvenile rats

2021 ◽  
Author(s):  
Kshitij Jadhav ◽  
Aurelien Bernheim ◽  
Lea Aeschlimann ◽  
Guylene Kirschmann ◽  
Isabelle Decosterd ◽  
...  

Development of self-regulatory competencies during adolescence is partially dependent on normative brain maturation. Here we report that juvenile rats as compared to adults exhibit impulsive and compulsive-like behavioral traits, the latter being associated with lower expression of mRNA levels of the immediate early gene zif268 in the anterior insula (AI). This observation suggests that deficits in AI function in juvenile rats could explain their immature pattern of interoceptive cue integration in rational decision-making and compulsive phenotype. In support of this, here we report hypoexcitability of juvenile layer-V pyramidal neurons in the AI, concomitant with reduced glutamatergic synaptic input to these cells. Chemogenetic activation of the AI attenuated the compulsive trait suggesting that delayed maturation of the AI results in suboptimal integration of sensory and cognitive information in adolescents and this contributes to inflexible behaviors in specific conditions of reward availability.

Neuroscience ◽  
2017 ◽  
Vol 358 ◽  
pp. 13-27 ◽  
Author(s):  
Hajime Sato ◽  
Tsutomu Kawano ◽  
Dong Xu Yin ◽  
Takafumi Kato ◽  
Hiroki Toyoda

2020 ◽  
Vol 22 (1) ◽  
pp. 259
Author(s):  
Hiroki Toyoda ◽  
Ayano Katagiri ◽  
Takafumi Kato ◽  
Hajime Sato

The pesticide rotenone inhibits mitochondrial complex I and is thought to cause neurological disorders such as Parkinson’s disease and cognitive disorders. However, little is known about the effects of rotenone on conditioned taste aversion memory. In the present study, we investigated whether intranasal administration of rotenone affects conditioned taste aversion memory in mice. We also examined how the intranasal administration of rotenone modulates synaptic transmission and plasticity in layer V pyramidal neurons of the mouse insular cortex that is critical for conditioned taste aversion memory. We found that the intranasal administration of rotenone impaired conditioned taste aversion memory to bitter taste. Regarding its cellular mechanisms, long-term depression (LTD) but not long-term potentiation (LTP) was impaired in rotenone-treated mice. Furthermore, spontaneous inhibitory synaptic currents and tonic GABA currents were decreased in layer V pyramidal neurons of rotenone-treated mice compared to the control mice. The impaired LTD observed in pyramidal neurons of rotenone-treated mice was restored by a GABAA receptor agonist muscimol. These results suggest that intranasal administration of rotenone decreases GABAergic synaptic transmission in layer V pyramidal neurons of the mouse insular cortex, the result of which leads to impairment of LTD and conditioned taste aversion memory.


Resuscitation ◽  
1997 ◽  
Vol 35 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Victor A Akulinin ◽  
Sergey S Stepanov ◽  
Valeriy V Semchenko ◽  
Pavel V Belichenko

Author(s):  
Ahlem Assali ◽  
Jennifer Y. Cho ◽  
Evgeny Tsvetkov ◽  
Abha R. Gupta ◽  
Christopher W. Cowan

AbstractAutism spectrum disorder (ASD) is characterized by impairments in social communication and interaction and restricted, repetitive behaviors. It is frequently associated with comorbidities, such as attention-deficit hyperactivity disorder, altered sensory sensitivity, and intellectual disability. A de novo nonsense mutation in EPHB2 (Q857X) was discovered in a female patient with ASD [13], revealing EPHB2 as a candidate ASD risk gene. EPHB2 is a receptor tyrosine kinase implicated in axon guidance, synaptogenesis, and synaptic plasticity, positioning it as a plausible contributor to the pathophysiology of ASD and related disorders. In this study, we show that the Q857X mutation produced a truncated protein lacking forward signaling and that global disruption of one EphB2 allele (EphB2+/−) in mice produced several behavioral phenotypes reminiscent of ASD and common associated symptoms. EphB2+/− female, but not male, mice displayed increased repetitive behavior, motor hyperactivity, and learning and memory deficits, revealing sex-specific effects of EPHB2 hypofunction. Moreover, we observed a significant increase in the intrinsic excitability, but not excitatory/inhibitory ratio, of motor cortex layer V pyramidal neurons in EphB2+/− female, but not male, mice, suggesting a possible mechanism by which EPHB2 hypofunction may contribute to sex-specific motor-related phenotypes. Together, our findings suggest that EPHB2 hypofunction, particularly in females, is sufficient to produce ASD-associated behaviors and altered cortical functions in mice.


2021 ◽  
Vol 118 (52) ◽  
pp. e2112212118
Author(s):  
Jiseok Lee ◽  
Joanna Urban-Ciecko ◽  
Eunsol Park ◽  
Mo Zhu ◽  
Stephanie E. Myal ◽  
...  

Immediate-early gene (IEG) expression has been used to identify small neural ensembles linked to a particular experience, based on the principle that a selective subset of activated neurons will encode specific memories or behavioral responses. The majority of these studies have focused on “engrams” in higher-order brain areas where more abstract or convergent sensory information is represented, such as the hippocampus, prefrontal cortex, or amygdala. In primary sensory cortex, IEG expression can label neurons that are responsive to specific sensory stimuli, but experience-dependent shaping of neural ensembles marked by IEG expression has not been demonstrated. Here, we use a fosGFP transgenic mouse to longitudinally monitor in vivo expression of the activity-dependent gene c-fos in superficial layers (L2/3) of primary somatosensory cortex (S1) during a whisker-dependent learning task. We find that sensory association training does not detectably alter fosGFP expression in L2/3 neurons. Although training broadly enhances thalamocortical synaptic strength in pyramidal neurons, we find that synapses onto fosGFP+ neurons are not selectively increased by training; rather, synaptic strengthening is concentrated in fosGFP− neurons. Taken together, these data indicate that expression of the IEG reporter fosGFP does not facilitate identification of a learning-specific engram in L2/3 in barrel cortex during whisker-dependent sensory association learning.


1983 ◽  
Vol 3 (8) ◽  
pp. 1333-1342
Author(s):  
J F Bond ◽  
S R Farmer

The expression of alpha-tubulin, beta-tubulin, and actin mRNA during rat brain development has been examined by using specific cDNA clones and in vitro translation techniques. During brain maturation (0 to 80 days postnatal), these mRNA species undergo a significant decrease in abundance. The kinetics of this decrease varies between the cerebrum and the cerebellum. These mRNAs are most abundant in both tissues during week 1 postnatal, each representing 10 to 15% of total mRNA activity. Both alpha- and beta-tubulin mRNA content decreases by 90 to 95% in the cerebrum after day 11 postnatal, and 70 to 80% decreases in the cerebellum after day 16. Actin sequences also decrease but to a lesser extent in both tissues (i.e., 50%). These decreases coincide with the major developmental morphological changes (i.e., neurite extension) occurring during this postnatal period. These studies have also identified the appearance of a new 2.5-kilobase beta-tubulin mRNA species, which is more predominant in the cerebellar cytoplasm. The appearance of this form occurs at a time when the major 1.8-kilobase beta-tubulin mRNA levels are declining. The possibility that the tubulin multigene family is phenotypically expressed and then this expression responds to the morphological state of the nerve cells is discussed.


2002 ◽  
Vol 87 (5) ◽  
pp. 2490-2504 ◽  
Author(s):  
Michelle Day ◽  
Patricia A. Olson ◽  
Josef Platzer ◽  
Joerg Striessnig ◽  
D. James Surmeier

There is growing evidence linking alterations in serotonergic signaling in the prefrontal cortex to the etiology of schizophrenia. Prefrontal pyramidal neurons are richly innervated by serotonergic fibers and express high levels of serotonergic 5-HT2-class receptors. It is unclear, however, how activation of these receptors modulates cellular activity. To help fill this gap, whole cell voltage-clamp and single-cell RT-PCR studies of acutely isolated layer V–VI prefrontal pyramidal neurons were undertaken. The vast majority (>80%) of these neurons had detectable levels of 5-HT2A or 5-HT2C receptor mRNA. Bath application of 5-HT2 agonists inhibited voltage-dependent Ca2+ channel currents. L-type Ca2+ channels were a particularly prominent target of this signaling pathway. The L-type channel modulation was blocked by disruption of Gαq signaling or by inhibition of phospholipase Cβ. Antagonism of intracellular inositol trisphosphate signaling, chelation of intracellular Ca2+, or depletion of intracellular Ca2+ stores also blocked this modulation. Inhibition of the Ca2+-dependent phosphatase calcineurin prevented receptor-mediated modulation of L-type currents. Last, the 5-HT2 receptor modulation was robustly expressed in neurons from Cav1.3 knockout mice. These findings argue that 5-HT2receptors couple through Gαq proteins to trigger a phospholipase Cβ/inositol trisphosphate signaling cascade resulting in the mobilization of intracellular Ca2+, activation of calcineurin, and inhibition of Cav1.2 L-type Ca2+currents. This modulation and its blockade by atypical neuroleptics could have wide-ranging effects on synaptic integration and long-term gene expression in deep-layer prefrontal pyramidal neurons.


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