Kainate Receptor-Mediated Modulation of Hippocampal Fast Spiking Interneurons in a Rat Model of Schizophrenia

Kainate receptor (KAR) subunits are believed to be involved in abnormal GABAergic neurotransmission in the hippocampus (HIPP) in schizophrenia (SZ) and bipolar disorder. Postmortem studies have shown changes in the expression of the GluR5/6 subunits of KARs in the stratum oriens (SO) of sectors CA2/3, where the basolateral amygdala (BLA) sends a robust projection. Previous work using a rat model of SZ demonstrated that BLA activation leads to electrophysiological changes in fast-spiking interneurons in SO of CA2/3. The present study explores KAR modulation of interneurons in CA2/3 in response to BLA activation. Intrinsic firing properties of these interneurons through KAR-mediated activity were measured with patch-clamp recordings from rats that received 15 days of picrotoxin infusion into the BLA. Chronic BLA activation induced changes in the firing properties of CA2/3 interneurons associated with modifications in the function of KARs. Specifically, the responsiveness of these interneurons to activation of KARs was diminished in picrotoxin-treated rats, while the after-hyperpolarization (AHP) amplitude was increased. In addition, we tested blockers of KAR subunits which have been shown to have altered gene expression in SO sector CA2/3 of SZ subjects. The GluR5 antagonist UBP296 further decreased AP frequency and increased AHP amplitude in picrotoxin-treated rats. Application of the GluR6/7 antagonist NS102 suggested that activation of GluR6/7 KARs may be required to maintain the high firing rates in SO interneurons in the presence of KA. Moreover, the GluR6/7 KAR-mediated signaling may be suppressed in PICRO-treated rats. Our findings indicate that glutamatergic activity from the BLA may modulate the firing properties of CA2/3 interneurons through GluR5 and GluR6/7 KARs. These receptors are expressed in GABAergic interneurons and play a key role in the synchronization of gamma oscillations. Modulation of interneuronal activity through KARs in response to amygdala activation may lead to abnormal oscillatory rhythms reported in SZ subjects

Functional maturation of CA1 synapses involves activity-dependent loss of tonic kainate receptor-mediated inhibition of glutamate release

SummaryEarly in development, excitatory synapses transmit with low efficacy, one mechanism for which is a low probability of transmitter release (Pr). However, little is known about the developmental mechanisms that control activity-dependent maturation of the presynaptic release. Here, we show that during early development, transmission at CA3-CA1 synapses is regulated by a high-affinity, G protein-dependent kainate receptor (KAR), which is endogenously activated by ambient glutamate. By tonically depressing glutamate release, this mechanism sets the dynamic properties of neonatal inputs to favor transmission during high frequency bursts of activity, typical for developing neuronal networks. In response to induction of LTP, the tonic activation of KAR is rapidly down regulated, causing an increase in Pr and profoundly changing the dynamic properties of transmission. Early development of the glutamatergic connectivity thus involves an activity-dependent loss of presynaptic KAR function producing maturation in the mode of excitatory transmission from CA3 to CA1

Comorbidities and medication use in Finnish patients with psoriasis:a population-based registry study

Abstract Therapeutic options for psoriasis vulgaris have changed during recent decades with the introduction of biologics. Few nationwide studies are available on psoriasis treatment patterns, and those from Finland predate the use of biologics. The aim of this retrospective, population-based registry study was to identify patients with psoriasis vulgaris and their treatment patterns in the secondary care setting in Finland. The study cohort included 41,456 adults with a diagnosis of psoriasis vulgaris in the public secondary healthcare setting from 2012 through 2018. Data on comorbidities, pharmacotherapy, and phototherapy were collected from nationwide healthcare and drug registries. Patients in the cohort had a wide range of comorbidities, with 14.9% having psoriatic arthritis. Treatment was based largely on topical and conventional systemic medications. Conventional medications were used by 28.9% of patients, and methotrexate was the most common option (20.9%). Biologics were used by 7.3% of patients, mostly as second- and third-line treatment. The use of conventional systemic medications, topical treatments, and phototherapy decreased after the initiation of biologics. This study of psoriasis vulgaris in Finland provides a framework for the development of future care practices

The association of body mass index with quality of life and working ability:a Finnish population-based study

Abstract Purpose: The impact of obesity on quality of life (QoL) and working ability vary in different dimensions. This study investigated the association of obesity with QoL and working ability in Finnish adults. Comorbidities as associative factors were also characterised. Methods: This cross-sectional study included 4956 randomly selected adults. QoL (EUROHIS-QOL 8 total score and individual components), perceived physical and psychological working ability, and sick leave days were analysed in different body mass index (BMI) groups. Regression models were used to study the role of comorbidities as associative factors. Results: EUROHIS-QOL 8 total score was significantly lower in BMI group 25.0–29.9 kg/m² (4.01; 95% confidence interval 3.97–4.05), BMI 30.0–34.9 kg/m² (3.85; 3.79–3.91), BMI 35.0–39.9 kg/m² (3.75; 3.66–3.85), and BMI ≥ 40.0 kg/m² (3.73; 3.46–4.00) compared to individuals with normal (18.5–24.9 kg/m²) BMI (4.08; 4.04–4.12). Individuals with obesity (BMI ≥ 30.0 kg/m²) rated their QoL lower than individuals with normal BMI in seven of the eight EUROHIS-QOL 8 components. A lesser proportion of individuals (53–73%) with obesity rated their physical working ability as very or fairly good compared to individuals with normal BMI (90%, p values < 0.001). The psychological working ability was rated as very or fairly good by 71–75% of individuals with obesity compared to 85% of individuals with normal BMI (p = 0.008 and p = 0.001 in individuals with BMI 30.0–34.9 and BMI 35.0–39.9 kg/m², respectively). Conclusions: Obesity was negatively associated with both physical and psychological components of QoL, even after accounting for obesity-related comorbidities. Obesity treatment can benefit from a holistic approach that considers these multifaceted associations