DNA cytosine methyltransferases differentially regulate genome-wide hypermutation and interhomolog recombination in Trichoderma reesei meiosis.

Trichoderma reesei is an economically important enzyme producer with several unique meiotic features. spo11, the initiator of meiotic double-strand breaks (DSBs) in most sexual eukaryotes, is dispensable for T. reesei meiosis. T. reesei lacks the meiosis-specific recombinase Dmc1. Rad51 and Sae2, the activator of the Mre11 endonuclease complex, promote DSB repair and chromosome synapsis in wild-type and spo11Δ meiosis. DNA methyltransferases (DNMTs) perform multiple tasks in meiosis. Three DNMT genes (rid1, dim2 and dimX) differentially regulate genome-wide cytosine methylation and C:G-to-T:A hypermutations in different chromosomal regions. We have identified two types of DSBs: type I DSBs require spo11 or rid1 for initiation, whereas type II DSBs do not rely on spo11 and rid1 for initiation. rid1 (but not dim2) is essential for Rad51-mediated DSB repair and normal meiosis. rid1 and rad51 exhibit a locus heterogeneity (LH) relationship, in which LH-associated proteins often regulate interconnectivity in protein interaction networks. This LH relationship can be suppressed by deleting dim2 in a haploid rid1Δ (but not rad51Δ) parental strain, indicating that dim2 and rid1 share a redundant function that acts earlier than rad51 during early meiosis. In conclusion, our studies provide the first evidence of the involvement of DNMTs during meiotic initiation and recombination.

Trichoderma reesei Rad51 tolerates mismatches in hybrid meiosis with diverse genome sequences.

Most eukaryotes possess two RecA-like recombinases (ubiquitous Rad51 and meiosis-specific Dmc1) to promote interhomolog recombination during meiosis. However, some eukaryotes have lost Dmc1. Given that mammalian and yeast Saccharomyces cerevisiae (Sc) Dmc1 have been shown to stabilize recombination intermediates containing mismatches better than Rad51, we used the Pezizomycotina filamentous fungus Trichoderma reesei to address if and how Rad51-only eukaryotes conduct interhomolog recombination in zygotes with high sequence heterogeneity. We applied multidisciplinary approaches (next- and third-generation sequencing technology, genetics, cytology, bioinformatics, biochemistry, and single-molecule biophysics) to show that T. reesei Rad51 (TrRad51) is indispensable for interhomolog recombination during meiosis and, like ScDmc1, TrRad51 possesses better mismatch tolerance than ScRad51 during homologous recombination. Our results also indicate that the ancestral TrRad51 evolved to acquire ScDmc1-like properties by creating multiple structural variations, including via amino acid residues in the L1 and L2 DNA-binding loops.

Inactivation of mitochondrial pyruvate carrier promotes NLRP3 inflammasome activation and gout development via metabolic reprogramming.

The nucleotide-binding and oligomerization domain, leucine-rich repeats, and pyrin domain-containing protein 3 (NLRP3) inflammasome plays a crucial role in innate immunity and is involved in the pathogenesis of autoinflammatory diseases. Glycolysis regulates NLRP3 inflammasome activation in macrophages. However, how lactic acid fermentation and pyruvate oxidation controlled by the mitochondrial pyruvate carrier (MPC) affect NLRP3 inflammasome activation and autoinflammatory disease remains elusive. We found that the inactivation of MPC with genetic depletion or pharmacological inhibitors, MSDC-0160 or pioglitazone, increased NLRP3 inflammasome activation and IL-1ß secretion in macrophages. Glycolytic reprogramming induced by MPC inhibition skewed mitochondrial ATP-associated oxygen consumption into cytosolic lactate production, which enhanced NLRP3 inflammasome activation in response to monosodium urate (MSU) crystals. As pioglitazone is an insulin sens MSDC-itizer used for diabetes, its MPC inhibitory effect in diabetic individuals was investigated. The results showed that MPC inhibition exacerbated MSU-induced peritonitis in diabetic mice and increased the risk of gout in patients with diabetes. Altogether, we found that glycolysis controlled by MPC regulated NLRP3 inflammasome activation and gout development. Accordingly, prescriptions for medications targeting MPC should consider the increased risk of NLRP3-related autoinflammatory diseases.

Self-polymerized platinum (II)-Polydopamine nanomedicines for photo-chemotherapy of bladder Cancer favoring antitumor immune responses.

Systemic administration of platinum-based drugs has obvious limitations in the treatment of advanced bladder cancer (BC) owing to lower tumor accumulation and uncontrolled release of chemotherapeutics. There is an urgent need for advanced strategies to overcome the current limitations of platinum-based chemotherapy, to achieve maximal therapeutic outcomes with reduced side effects. In this study, self-polymerized platinum (II)-polydopamine nanocomplexes (PtPDs) were tailored for efficient chemo-photoimmunotherapy of BC. PtPDs with high Pt loading content (11.3%) were degradable under the combination of a reductive tumor microenvironment and near-infrared (NIR) light irradiation, thus controlling the release of Pt ions to achieve efficient chemotherapy. In addition, polydopamine promoted stronger photothermal effects to supplement platinum-based chemotherapy. Consequently, PtPDs provided effective chemo-photothermal therapy of MB49 BC in vitro and in vivo, strengthening the immunogenic cell death (ICD) effect and robust anti-tumoral immunity response. When combined with a PD-1 checkpoint blockade, PtPD-based photochemotherapy evoked systemic immune responses that completely suppressed primary and distant tumor growth without inducing systemic toxicities. Our work provides a highly versatile approach through metal-dopamine self-polymerization for the precise delivery of metal-based chemotherapeutic drugs, and may serve as a promising nanomedicine for efficient and safe platinum-based chemotherapy for BC.

Are perceived containment and coping styles differentially associated with reactive and proactive aggression?

Studies informing ways to target aggression in youth, particularly through the identification of internal patterns predictive of concurrent and future levels of aggression, could be particularly beneficial. To this end, the current study surveyed 216 elementary-aged children on topics of perceived containment (i.e., perceived ability of authority figures to control, limit, and set consequences for one's behaviors), coping responses, and reactive (RA) and proactive aggression (PA). Using multilevel modeling, the individual and interactive effects of coping responses and perceived containment on aggression within time and across two school years were examined. Within time, lower levels of perceived containment were associated with greater RA and PA. Passive coping was also positively associated with RA. The relation between perceived containment and RA within time was dependent on humor, whereas the relation between perceived containment and PA depended on problem-solving. Across time, while T1 passive coping predicted the trajectory of both functions of aggression, a greater number of T1 coping responses predicted the slope of RA with problem-solving and friend support-seeking as well as T1 perceived containment also predicting the trajectory of RA. No coping responses moderated the relation between T1 perceived containment and the trajectory of RA. In contrast, humor moderated the influence of T1 perceived containment and the trajectory of PA. Findings give insight into the ways internal processes of perceived containment and coping are associated with patterns of aggression in elementary-aged youth. This work is valuable in identifying several potential areas for prevention and intervention research.

Pediatric Tube Weaning: A Meta-Analysis of Factors Contributing to Success.

Approximately 3-10% of children have severe feeding issues, and some require enteral/tube nutrition to grow and thrive. For many children, tube feeding is temporary, making efficacious interventions for tube weaning essential. We conducted a systematic review and meta-analysis of tube weaning treatments. Outcomes included percentage of participants completely weaned from the tube, and mean percentage of kilocalories consumed orally following treatment. Data were extracted from 42 studies, including cohort studies and single-subject research design studies. We evaluated moderators of treatment success, including treatment setting, use of behavioral approaches, use of hunger provocation, and use of a multidisciplinary approach. Results indicated that, after treatment, children received significantly more calories orally, and 67-69% of children were fully weaned. These analyses suggest that current interventions are generally effective; however, variability within treatments exist. Prospective randomized clinical trials are needed to understand effective components of weaning interventions.

Dual roles of yeast Rad51 N-terminal domain in repairing DNA double-strand breaks.

Highly toxic DNA double-strand breaks (DSBs) readily trigger the DNA damage response (DDR) in cells, which delays cell cycle progression to ensure proper DSB repair. In Saccharomyces cerevisiae, mitotic S phase (20-30 min) is lengthened upon DNA damage. During meiosis, Spo11-induced DSB onset and repair lasts up to 5 h. We report that the NH2-terminal domain (NTD; residues 1-66) of Rad51 has dual functions for repairing DSBs during vegetative growth and meiosis. Firstly, Rad51-NTD exhibits autonomous expression-enhancing activity for high-level production of native Rad51 and when fused to exogenous ß-galactosidase in vivo. Secondly, Rad51-NTD is an S/T-Q cluster domain (SCD) harboring three putative Mec1/Tel1 target sites. Mec1/Tel1-dependent phosphorylation antagonizes the proteasomal degradation pathway, increasing the half-life of Rad51 from ∼30 min to ≥180 min. Our results evidence a direct link between homologous recombination and DDR modulated by Rad51 homeostasis.

Budding yeast Rad51: a paradigm for how phosphorylation and intrinsic structural disorder regulate homologous recombination and protein homeostasis.

The RecA-family recombinase Rad51 is the central player in homologous recombination (HR), the faithful pathway for repairing DNA double-strand breaks (DSBs) during both mitosis and meiosis. The behavior of Rad51 protein in vivo is fine-tuned via posttranslational modifications conducted by multiple protein kinases in response to cell cycle cues and DNA lesions. Unrepaired DSBs and ssDNA also activate Mec1ATR and Tel1ATM family kinases to initiate the DNA damage response (DDR) that safeguards genomic integrity. Defects in HR and DDR trigger genome instability and result in cancer predisposition, infertility, developmental defects, neurological diseases or premature aging. Intriguingly, yeast Mec1ATR- and Tel1ATM-dependent phosphorylation promotes Rad51 protein stability during DDR, revealing how Mec1ATR can alleviate proteotoxic stress. Moreover, Mec1ATR- and Tel1ATM-dependent phosphorylation also occurs on DDR-unrelated proteins, suggesting that Mec1ATR and Tel1ATM have a DDR-independent function in protein homeostasis. In this minireview, we first describe how human and budding yeast Rad51 are phosphorylated by multiple protein kinases at different positions to promote homology-directed DNA repair and recombination (HDRR). Then, we discuss recent findings showing that intrinsic structural disorder and Mec1ATR/Tel1ATM-dependent phosphorylation are coordinated in yeast Rad51 to regulate both HR and protein homeostasis.

S. cerevisiae Mre11 recruits conjugated SUMO moieties to facilitate the assembly and function of the Mre11-Rad50-Xrs2 complex.

Double-strand breaks (DSBs) in chromosomes are the most challenging type of DNA damage. The yeast and mammalian Mre11-Rad50-Xrs2/Nbs1 (MRX/N)-Sae2/Ctp1 complex catalyzes the resection of DSBs induced by secondary structures, chemical adducts or covalently-attached proteins. MRX/N also initiates two parallel DNA damage responses-checkpoint phosphorylation and global SUMOylation-to boost a cell's ability to repair DSBs. However, the molecular mechanism of this SUMO-mediated response is not completely known. In this study, we report that Saccharomyces cerevisiae Mre11 can non-covalently recruit the conjugated SUMO moieties, particularly the poly-SUMO chain. Mre11 has two evolutionarily-conserved SUMO-interacting motifs, Mre11(SIM1) and Mre11(SIM2), which reside on the outermost surface of Mre11. Mre11(SIM1) is indispensable for MRX assembly. Mre11(SIM2) non-covalently links MRX with the SUMO enzymes (E2/Ubc9 and E3/Siz2) to promote global SUMOylation of DNA repair proteins. Mre11(SIM2) acts independently of checkpoint phosphorylation. During meiosis, the mre11(SIM2) mutant, as for mre11S, rad50S and sae2Δ, allows initiation but not processing of Spo11-induced DSBs. Using MRX and DSB repair as a model, our work reveals a general principle in which the conjugated SUMO moieties non-covalently facilitate the assembly and functions of multi-subunit protein complexes.

[Ruyi Jinhuang Plaster suppresses BPH by reducing the expressions of P38, JNK2, NF-кBP65 and STAT3 in the prostate tissue of rats].

OBJECTIVE: To investigate the effect of Ruyi Jinhuang Plaster (RJP) on testosterone propionate-induced BPH in the rat model and its action mechanisms. METHODS: Forty-eight SD male rats were randomly divided into six groups of equal number: normal control, BPH model control, finasteride, and high-, medium- and low-dose RJP. The BPH model was made in the latter five groups by hypodermic injection of testosterone propionate. From the first day of modeling, the rats of the normal control and BPH model control groups were treated with blank plasters and those of the high-, medium- and low-dose RJP groups with RJPs at 42.0, 21.0 and 10.5 cm2/kg applied to the dehaired area of the back, and those of the finasteride group by gavage of finasteride at 4.5 mg/kg, all once a day for 30 successive days. Then the prostates of the animals were harvested for observation of histopathological changes by HE staining, measurement of the areas of interstitial and epithelial cells and prostatic glandular cavity, and determination of the expressions of P38, JNK2, NF-кBP65 and STAT3 proteins in the prostate tissue by Western blot. RESULTS: Compared with the BPH model controls, the high-dose RJP group showed significantly decreased proliferation and area proportion of prostatic epithelial cells (P < 0.05), increased area proportion of the prostatic glandular cavity (P < 0.05), and reduced expressions of P38, p-P38, NF-кBP65, P-NF-кBP65, STAT3, P-STAT3 and JNK2 in the prostate tissue (P < 0.05); the medium-dose RJP group exhibited markedly down-regulated expressions of JNK2 and NF-кBP65 (P < 0.05) but an up-regulated level of p-JNK (P < 0.05); while the low-dose RJP group displayed a remarkably reduced expression of JNK2 (P < 0.05) but an elevated level of p-JNK (P < 0.05). CONCLUSIONS: RJP suppresses BPH in the model rat by down-regulating the expressions of P38, p-P38, NF-кBP65, P-NF-кBP65, STAT3, P-STAT3 and JNK2 or up-regulating that of p-JNK in the prostate tissue.

Avoidance of antibiotic administration to Campylobacter enterocolitis mimicking severe salmonellosis by clinical and laboratory features.

BACKGROUND: To compare the clinical and laboratory features of non-typhoid Salmonella (NTS) and Campylobacter jejuni enterocolitis in children and formulate a risk scoring system (with receiver-operating characteristic curve) to facilitate early decision making and avoid antibiotic overuse in C. jejuni enterocolitis. METHODS: Between January 2008 and December 2011, children (age <18 years) diagnosed as having C. jejuni enterocolitis and NTS enterocolitis in Kaohsiung Chang Gung Memorial Hospital were retrospectively enrolled. Clinical features and laboratory data were collected for analysis and a risk calculation score is created for the identification of Campylobacter infections. RESULTS: A total of 309 cases of C. jejuni enterocolitis and 496 cases of NTS enterocolitis were enrolled. Compared with Salmonella group clinically, the Campylobacter group had older age (81.06 ± 50.65 vs. 32.70 ± 34.88 months, p <; 0.001), more abdominal pain (69.26% vs. 37.5%, p <; 0.001) and more watery diarrhea (79.94% vs. 20.77%, p <; 0.001). In laboratory data, the Campylobacter group had higher level of white blood cell count (11 208 ± 4380 vs. 9095 ± 3598 cell/mm3, p <; 0.001). CONCLUSION: Four criteria including age (≥5 years), leukocytosis (≥10 000 cell/mm3), abdominal pain and watery diarrhea were identified as good predictors of Campylobacter enterocolitis. When three criteria were fulfilled, Campylobacter enterocolitis was highly suspected and antibiotic could be withheld even when C-reactive protein is high and before stool culture results are known. When four criteria were fulfilled, antibiotic usage was absolutely unnecessary.

Mek1 stabilizes Hop1-Thr318 phosphorylation to promote interhomolog recombination and checkpoint responses during yeast meiosis.

Red1, Hop1 and Mek1 are three yeast meiosis-specific chromosomal proteins that uphold the interhomolog (IH) bias of meiotic recombination. Mek1 is also an effector protein kinase in a checkpoint that responds to aberrant DNA and/or axis structure. The activation of Mek1 requires Red1-dependent Hop1-Thr(T)318 phosphorylation, which is mediated by Mec1 and Tel1, the yeast homologs of the mammalian DNA damage sensor kinases ATR and ATM. As the ectopic expression of Mek1-glutathione S-transferase (GST) was shown to promote IH recombination in the absence of Mec1/Tel1-dependent checkpoint function, it was proposed that Mek1 might play dual roles during meiosis by directly phosphorylating targets that are involved in the recombination checkpoint. Here, we report that Mek1 has a positive feedback activity in the stabilization of Mec1/Tel1-mediated Hop1-T318 phosphorylation against the dephosphorylation mediated by protein phosphatase 4. Our results also reveal that GST-Mek1 or Mek1-GST further increases Hop1-T318 phosphorylation. This positive feedback function of Mek1 is independent of Mek1's kinase activity, but dependent on Mek1's forkhead-associated (FHA) domain and its arginine 51 residue. Arginine 51 directly mediates the interaction of Mek1-FHA and phosphorylated Hop1-T318. We suggest that the Hop1-Mek1 interaction is similar to the Rad53-Dun1 signaling pathway, which is mediated through the interaction of phosphorylated Rad53 and Dun1-FHA.

[Transurethral bipolar plasmakinetic enucleation and resection versus transurethral bipolar plasmakinetic resection of the prostate for BPH: a randomized controlled trial on the incidence of postoperative urinary incontinence].

OBJECTIVE: To compare the incidence rates of postoperative urinary incontinence between transurethral bipolar plasmakinetic enucleation and resection of the prostate (PKERP) and transurethral bipolar plasmakinetic resection of the prostate (PKRP), and provide evidence for the clinical application of PKERP. METHODS: Totally, 180 BPH patients were equally and randomly assigned to undergo PKERP and PKRP, respectively. We measured the urinary incontinence of the patients by pad test at 24 hours after extubation and every week after surgery for 4 weeks. Meanwhile, we recorded and compared the PSA level, prostate volume, Qmax, residual urine, IPSS, QOL, and the results of pad test between the two groups before and after surgery. RESULTS: The incidence rates of urinary incontinence in the PKERP and PKRP groups were 35.56% and 18.89% (P < 0.01) at 24 hours after extubation, 20.00% and 7.78% at 1 week after surgery (P < 0.05), and 3.33% and 2.22% at 2 weeks. There was no significant difference in the severity of urinary incontinence between the two groups at any time point (P > 0.05). No permanent urinary incontinence was observed in either group. CONCLUSION: Compared with PKRP, PKERP has a higher incidence rate of short-term urinary incontinence in the treatment of BPH, but not that of genuine incontinence, with similar severity and recovery time.

Parallel processing modeling in longitudinal designs: An example predicting trajectories of distress and life satisfaction.

PURPOSE: Parallel process modeling (PPM) can be used to analyze co-occurring relationships between health and psychological variables over time. A demonstration is provided using data obtained from the British Household Panel Survey (years 2005, 2006, 2007, and 2008), examining predictors of ongoing changes in their distress and life satisfaction of a subsample from the survey. RESEARCH METHOD: In the 2005 survey, data were available from 7,970 participants based on the following demographic variables: gender, age, ever registered as disabled, and ever experienced any strokes (before or at 2005). Time-varying variables included distress and life satisfaction collected yearly from 2005 to 2008. Time-invariant variables included age (65 or older), gender, disability condition, and stroke survivor status. RESULTS: Steps of fitting the PPM are presented. Four distinct distress trajectory groups-chronic, recovery, delayed, and resilient-were identified from the PPM estimates. Resilient and recovery groups showed a positive trend in life satisfaction. The delayed distress and chronic groups had a slight decrease in satisfaction. The time-invariant covariates only significantly predicted baseline levels of distress and satisfaction (i.e., their intercepts). CONCLUSIONS: PPM is a relatively simple and powerful tool for simultaneously studying relations between multiple processes. A step-by-step approach on decomposing the significant predictive relation from the change of distress to the change of satisfaction is presented. Properly decomposing any significant growth factor regressed on another growth factor is necessary to fully comprehend the intricate relationships within the results. Practical implications and additional methodological information about fitting PPM are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Noncanonical usage of stop codons in ciliates expands proteins with structurally flexible Q-rich motifs.

Serine(S)/threonine(T)-glutamine(Q) cluster domains (SCDs), polyglutamine (polyQ) tracts and polyglutamine/asparagine (polyQ/N) tracts are Q-rich motifs found in many proteins. SCDs often are intrinsically disordered regions that mediate protein phosphorylation and protein-protein interactions. PolyQ and polyQ/N tracts are structurally flexible sequences that trigger protein aggregation. We report that due to their high percentages of STQ or STQN amino acid content, four SCDs and three prion-causing Q/N-rich motifs of yeast proteins possess autonomous protein expression-enhancing activities. Since these Q-rich motifs can endow proteins with structural and functional plasticity, we suggest that they represent useful toolkits for evolutionary novelty. Comparative Gene Ontology (GO) analyses of the near-complete proteomes of 26 representative model eukaryotes reveal that Q-rich motifs prevail in proteins involved in specialized biological processes, including Saccharomyces cerevisiae RNA-mediated transposition and pseudohyphal growth, Candida albicans filamentous growth, ciliate peptidyl-glutamic acid modification and microtubule-based movement, Tetrahymena thermophila xylan catabolism and meiosis, Dictyostelium discoideum development and sexual cycles, Plasmodium falciparum infection, and the nervous systems of Drosophila melanogaster, Mus musculus and Homo sapiens. We also show that Q-rich-motif proteins are expanded massively in 10 ciliates with reassigned TAAQ and TAGQ codons. Notably, the usage frequency of CAGQ is much lower in ciliates with reassigned TAAQ and TAGQ codons than in organisms with expanded and unstable Q runs (e.g. D. melanogaster and H. sapiens), indicating that the use of noncanonical stop codons in ciliates may have coevolved with codon usage biases to avoid triplet repeat disorders mediated by CAG/GTC replication slippage.

Associations Between Maternal Negative Affectivity and Young Children's Disruptive Behavior Problems: The Mediating Effect of Callous-Unemotional Traits.

The current study examined associations between maternal negative affectivity (NA) and child disruptive behavior problems. The mediating role of child callous-unemotional (CU) traits in these relationships was also investigated. A multilevel mediation modeling approach was adopted using a sample of 100 families with children between 2.5 and 5.5 years of age (N = 201; mean age = 3.8, standard deviation = 1.0). The mediation models showed significant mediating effects of maternal NA through CU traits for ADHD (ß = 0.12, p<.01), ODD (ß =0.13, p<.01), and aggression (ß =0.16, p<.001), and a significant direct effect for aggression (ß = 0.12, p<.05). A structural equation modeling analysis was also performed, and overall, the results were consistent with that from mediation models, which suggested that child CU traits were significantly correlated with maternal NA (ß = 0.252, p<.001), ADHD (ß = 0.504, p<.001), ODD (ß = 0.545, p<.001), and aggression (ß = 0.686, p<.001). Our results indicated that maternal NA could serve as a potential risk factor for child CU, which, in turn, may contribute to disruptive behavior during early childhood.

Sensory cortex plasticity supports auditory social learning.

Social learning (SL) through experience with conspecifics can facilitate the acquisition of many behaviors. Thus, when Mongolian gerbils are exposed to a demonstrator performing an auditory discrimination task, their subsequent task acquisition is facilitated, even in the absence of visual cues. Here, we show that transient inactivation of auditory cortex (AC) during exposure caused a significant delay in task acquisition during the subsequent practice phase, suggesting that AC activity is necessary for SL. Moreover, social exposure induced an improvement in AC neuron sensitivity to auditory task cues. The magnitude of neural change during exposure correlated with task acquisition during practice. In contrast, exposure to only auditory task cues led to poorer neurometric and behavioral outcomes. Finally, social information during exposure was encoded in the AC of observer animals. Together, our results suggest that auditory SL is supported by AC neuron plasticity occurring during social exposure and prior to behavioral performance.

Cannabinoid transmission in the basolateral amygdala modulates fear memory formation via functional inputs to the prelimbic cortex.

The cannabinoid CB1 receptor system is critically involved in the control of associative fear memory formation within the amygdala-prefrontal cortical pathway. The CB1 receptor is found in high concentrations in brain structures that are critical for emotional processing, including the basolateral amygdala (BLA) and the prelimbic division (PLC) of the medial prefrontal cortex (mPFC). However, the precise role of CB1 receptor transmission within the BLA during the processing of fear memory is not fully understood. We examined the potential role of BLA CB1 receptor transmission during an olfactory fear-conditioning procedure in rats by pharmacologically modulating CB1 cannabinoid transmission directly within the BLA. We report that blockade of BLA CB1 receptor transmission prevents the acquisition of associative fear memory, while having no effect on the recall or consolidation of these memories. In contrast, intra-BLA activation of CB1 receptor transmission or blockade of endocannabinoid reuptake strongly potentiated the emotional salience of normally subthreshold fear-conditioning stimuli. In addition, pharmacological inactivation of the mPFC before intra-BLA CB1 activation blocked CB1-receptor-mediated potentiation of fear memory formation. In vivo single-unit electrophysiological recordings within the PLC revealed that modulation of BLA CB1 receptor transmission strongly influences neuronal activity within subpopulations of PLC neurons, with blockade of intra-BLA CB1 receptor transmission inhibiting spontaneous PLC neuronal activity and activation of CB1 receptors producing robust activation, in terms of neuronal firing frequency and bursting activity. Thus, cannabinoid transmission within the BLA strongly modulates the processing of associative fear memory via functional interactions with PLC neuronal populations.

Identification of a dopamine receptor-mediated opiate reward memory switch in the basolateral amygdala-nucleus accumbens circuit.

The basolateral amygdala (BLA), ventral tegmental area (VTA), and nucleus accumbens (NAc) play central roles in the processing of opiate-related associative reward learning and memory. The BLA receives innervation from dopaminergic fibers originating in the VTA, and both dopamine (DA) D1 and D2 receptors are expressed in this region. Using a combination of in vivo single-unit extracellular recording in the NAc combined with behavioral pharmacology studies, we have identified a double dissociation in the functional roles of DA D1 versus D2 receptor transmission in the BLA, which depends on opiate exposure state; thus, in previously opiate-naive rats, blockade of intra-BLA D1, but not D2, receptor transmission blocked the acquisition of associative opiate reward memory, measured in an unbiased conditioned place preference procedure. In direct contrast, in rats made opiate dependent and conditioned in a state of withdrawal, intra-BLA D2, but not D1, receptor blockade blocked opiate reward encoding. This functional switch was dependent on cAMP signaling as comodulation of intra-BLA cAMP levels reversed or replicated the functional effects of intra-BLA D1 or D2 transmission during opiate reward processing. Single-unit in vivo extracellular recordings performed in neurons of the NAc confirmed an opiate-state-dependent role for BLA D1/D2 transmission in NAc neuronal response patterns to morphine. Our results characterize and identify a novel opiate addiction switching mechanism directly in the BLA that can control the processing of opiate reward information as a direct function of opiate exposure state via D1 or D2 receptor signaling substrates.