RESUMEN
Metaplasticity, defined as the plasticity of synaptic plasticity, could affect learning and memory at different neural levels. It was hypothesized that metaplasticity changes on glutamate receptors may affect memory destabilization, promoting or preventing reconsolidation. We investigated the metaplastic effect of NMDA channel blocker MK-801 on sucrose instrumental memory reconsolidation in a behavioural rat model associated to the assessment of molecular markers of metaplasticity, memory retrieval, destabilization and reconsolidation. Following instrumental conditioning and forced abstinence, rats were intraperitoneally treated with MK-801 or vehicle 24â¯h before the exposure to memory retrieval or not-retrieval. Separate groups were tested for in-vivo extinction of responding (24â¯h and 7â¯d after reactivation) or ex-vivo assessment of transcription factor Zif268 and ribosomal protein rpS6 phosphorylation in nucleus accumbens (NAc) and amygdala (Amy). MK-801 significantly inhibited instrumental responding at extinction test, suggesting reconsolidation blockade of instrumental memory. The decrease of Zif268 and phosphorylated-rpS6 levels in NAc and Amy in MK-801/Retrieval vs. Vehicle/Retrieval group supported the behavioural findings. An increase of GluN2B, GluA1 and mGluR5 in NAc, and GluN2B in Amy, 24â¯h after MK-801 indicated the trigger of associated metaplastic changes. Our findings show that metaplastic changes induced by NMDA receptors blockade affected sucrose instrumental memory retrieval as shown by both behavioural and molecular changes. We hypothesize that these findings however suggested a switch to extinction rather than a reconsolidation.
Asunto(s)
Encéfalo/fisiología , Condicionamiento Operante/fisiología , Consolidación de la Memoria/fisiología , Plasticidad Neuronal , Receptores de N-Metil-D-Aspartato/fisiología , Animales , Encéfalo/efectos de los fármacos , Condicionamiento Operante/efectos de los fármacos , Maleato de Dizocilpina/administración & dosificación , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Antagonistas de Aminoácidos Excitadores/administración & dosificación , Masculino , Consolidación de la Memoria/efectos de los fármacos , Plasticidad Neuronal/efectos de los fármacos , Subunidades de Proteína/metabolismo , Ratas Sprague-Dawley , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Proteína S6 Ribosómica/metabolismo , Sacarosa/administración & dosificaciónRESUMEN
Ketamine is a drug of abuse with a unique profile, which besides its inherent mechanism of action as a non-competitive antagonist of the NMDA glutamate receptor, displays both antidepressant and reinforcing properties. The major aim of our study was to find a molecular signature of ketamine that may help in discriminating between its reinforcing and antidepressant effects. To this end, we focused our attention on BDNF, a neurotrophin that has been shown to play a role in both antidepressant and reinforcing properties of several drugs. Rats were exposed to self-administer intravenous (IV) ketamine (S/A) for 43 days or to receive a single IV ketamine 0.5mg/kg, or vehicle infusion. Although the dose we employed is lower than that reported by the literature, it however yields Cmax values that correspond to those achieved in humans after antidepressant treatment. Our results show that while the single infusion of ketamine increased the neurotrophin expression in the hippocampus while reducing it in the ventral striatum, a feature shared with other antidepressants, the repeated self-administration reduced mBDNF expression and its downstream signalling in both ventral striatum and hippocampus. Further, we here show that phosphorylation of Akt is oppositely regulated by ketamine, pointing to this pathway as central to the different actions of the drug. Taken together, we here point to BDNF and its downstream signalling pathway as a finely tuned mechanism whose modulation might subserve the different features of ketamine.
Asunto(s)
Antidepresivos/farmacología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Ketamina/farmacología , Refuerzo en Psicología , Animales , Antidepresivos/administración & dosificación , Encéfalo/metabolismo , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Infusiones Intravenosas , Ketamina/administración & dosificación , Masculino , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Autoadministración , Transducción de SeñalRESUMEN
The conclusions of the EFSA following the peer review of the initial risk assessment carried out by the competent authority of the rapporteur Member State, Spain, for the pesticide active substance difenoconazole are reported. The context of the peer review was that requested by the European Commission following the submission and evaluation of confirmatory information with regard to the consumer risk assessment. The conclusions were reached on the basis of the evaluation of the representative uses of difenoconazole as a fungicide on pome fruit, carrot, wheat, barley, triticale, rye and oats. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and/or literature in the dossier peer reviewed, are presented. Concerns were not identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Greece, and co-rapporteur Member State, France, for the pesticide active substance paraffin oil are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of paraffin oil as an acaricide and insecticide on potatoes, ornamentals (flower bulbs) and orchards (pear/apple), on pome fruit and stone fruit, on field and permanent protected fruiting vegetables and on field and permanent protected roses and on citrus. The reliable end points appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Finland, and co-rapporteur Member State, Estonia, for the pesticide active substance mepiquat (evaluated variant mepiquat chloride) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of mepiquat chloride as a plant growth regulator on cereals and grass (field uses). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.
RESUMEN
The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State Belgium for the pesticide active substance Pythium oligandrum strain B301 and the considerations as regards the inclusion of the substance in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of Pythium oligandrum strain B301 as a resistance inducer/elicitor to control trunk diseases on grapevines. The reliable endpoints, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Belgium, and co-rapporteur Member State, Austria, for the pesticide active substance lenacil are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of lenacil as a herbicide on sugar and fodder beet (field use). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State The Netherlands for the pesticide active substance 1-methylcyclopropene are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council for an amendment in approval conditions. The current approval of 1-methylcyclopropene includes the specific provision 'Only uses as plant growth regulator for post-harvest storage in sealable warehouse may be authorised'. The applicant AgroFresh Holding France SAS submitted, in accordance with Article 7 of Reg. (EC) 1107/2009, an application to remove this specific provision in order to allow member states to authorise the use of products containing 1-methylcyclopropene on outdoor crops pre-harvest. The conclusions were reached on the basis of the evaluation of the representative use(s) of 1-methylcyclopropene as a plant growth regulator via spray application on pome fruit. The reliable endpoints, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Poland and co-rapporteur Member State Hungary for the pesticide active substance triclopyr (variant triclopyr-butotyl) and the assessment of applications for maximum residue levels (MRLs) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of triclopyr (variant triclopyr-butotyl) as a herbicide on established pasture and non-recreational amenity grassland (field use). MRLs were assessed in rice. The reliable end points, appropriate for use in regulatory risk assessment and the proposed MRLs, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, The Netherlands for the pesticide active substance Phthorimaea operculella granulovirus are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of Phthorimaea operculella granulovirus as an insecticide on tomato (field and greenhouse uses) and on potato (field use) via spraying (tractor drawn or knapsack sprayers) or overhead irrigation. The reliable endpoints, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed.
RESUMEN
The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Ireland, and co-rapporteur Member State, Poland, for the pesticide active substance dichlorprop-P and the variant dichlorprop-P-2-ethylhexyl and the assessment of applications for maximum residue levels (MRLs) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative uses of dichlorprop-P as a herbicide on cereals, grassland and grass seed crops and of the variant dichlorprop-P-2-ethylhexyl as a plant growth regulator on citrus. MRLs were assessed in mandarin and lemon. The conclusions from 2018 were updated in 2024 following the request from the European Commission with regard to the endocrine-disrupting properties. The reliable end points, appropriate for use in regulatory risk assessment and the proposed MRLs, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, Malta, for the pesticide active substance clove oil are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions for the amendment of approval were reached on the basis of the evaluation of the representative use of clove oil as a preharvest nematicide on tomatoes and cucumbers (permanent greenhouse use). The representative use evaluated for the renewal of approval of clove oil was as post-harvest fungicide and bactericide on apples, pears and peaches (indoor uses). The reliable endpoints appropriate for use in regulatory risk assessment are presented. Endpoints not relevant to the scope of the proposed amendment of approval conditions will be addressed in the context of the renewal of approval procedure of clove oil running in parallel (AIR IV, EFSA Q-2016-00809). Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Spain, and co-rapporteur Member State, the Netherlands, for the pesticide active substance quinolin-8-ol are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative use of quinolin-8-ol as a fungicide and bactericide against soil-borne pathogens in tomato cultivation in permanent greenhouses applied by drip irrigation. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, France, and co-rapporteur Member State, Austria, for the pesticide active substance pydiflumetofen and the assessment of applications for maximum residue levels (MRLs) are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of pydiflumetofen as a fungicide field application on pome fruits, grapes, potato, fruiting vegetables, cucurbits and Brassica vegetables and updated following the request from Commission to consider additional information submitted and review the risk assessment. The reliable endpoints, appropriate for use in regulatory risk assessment and the proposed MRLs, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The European Commission asked EFSA to revise the risk assessment for honey bees, bumble bees and solitary bees. This guidance document describes how to perform risk assessment for bees from plant protection products, in accordance with Regulation (EU) 1107/2009. It is a review of EFSA's existing guidance document, which was published in 2013. The guidance document outlines a tiered approach for exposure estimation in different scenarios and tiers. It includes hazard characterisation and provides risk assessment methodology covering dietary and contact exposure. The document also provides recommendations for higher tier studies, risk from metabolites and plant protection products as mixture.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, the Netherlands, for the pesticide active substance (3E)-dec-3-en-2-one and the considerations as regards the inclusion of the substance in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative post-harvest use of (3E)-dec-3-en-2-one on potato as a sprouting inhibitor applied by hot fogging in potato storage rooms. The reliable endpoints, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State France and co-rapporteur Member State Slovenia for the pesticide active substance sulfur and the considerations as regards the inclusion of the substance in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of sulfur as a fungicide and acaricide on grapevine and cereals (wheat, barley, oat, rye, triticale). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, the Netherlands and co-rapporteur Member State, the United Kingdom, for the pesticide active substance ethephon are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative use of ethephon as a plant growth regulator on cereals (winter and spring barley, winter and spring wheat, winter rye, winter triticale, spelt, durum wheat). The reliable endpoints appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Czech Republic, and co-rapporteur Member State, France, for the pesticide active substance fat distillation residues are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of fat distillation residues as a repellent on seedlings of coniferous and deciduous trees. The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns were not identified.
RESUMEN
The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Germany and co-rapporteur Member State France for the pesticide active substance S-metolachlor are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. In September 2022, the European Commission asked EFSA to deliver its conclusion on the available outcomes of the assessments in all areas excluding the full assessment of endocrine disrupting properties as several critical areas of concern related to the protection of the environment were identified. The conclusions were reached on the basis of the evaluation of the representative uses of S-metolachlor as a herbicide on maize and sunflower. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. The concerns identified are presented.