Enriched Environment Modulates Sharp Wave-Ripple (SPW-R) Activity in Hippocampal Slices.

Behavioral flexibility depends on neuronal plasticity which forms and adapts the central nervous system in an experience-dependent manner. Thus, plasticity depends on interactions between the organism and its environment. A key experimental paradigm for studying this concept is the exposure of rodents to an enriched environment (EE), followed by studying differences to control animals kept under standard conditions (SC).

Transient Oxygen-Glucose Deprivation Causes Region- and Cell Type-Dependent Functional Deficits in the Mouse Hippocampus .

Neurons are highly vulnerable to conditions of hypoxia-ischemia (HI) such as stroke or transient ischemic attacks. Recovery of cognitive and behavioral functions requires re-emergence of coordinated network activity, which, in turn, relies on the well-orchestrated interaction of pyramidal cells (PYRs) and interneurons. We therefore modelled HI in the mouse hippocampus, a particularly vulnerable region showing marked loss of PYR and fast-spiking interneurons (FSIs) after hypoxic-ischemic insults.

Rapid Support for Older Adults during the Initial Stages of the COVID-19 Pandemic: Results from a Geriatric Psychiatry Helpline.

Background: The COVID-19 pandemic and governmental lockdown measures disproportionally impact older adults. This study presents the results from a psychiatric helpline for older adults in Mannheim, Germany, during the lockdown, set up to provide information and psychosocial support. We aim to elucidate the needs of older adults, their reported changes, and the psychological impact during the initial stages of the health crisis.

Mild metabolic stress is sufficient to disturb the formation of pyramidal cell ensembles during gamma oscillations.

Disturbances of cognitive functions occur rapidly during acute metabolic stress. However, the underlying mechanisms are not fully understood. Cortical gamma oscillations (30-100 Hz) emerging from precise synaptic transmission between excitatory principal neurons and inhibitory interneurons, such as fast-spiking GABAergic basket cells, are associated with higher brain functions, like sensory perception, selective attention and memory formation.

Amyloid, APP, and Electrical Activity of the Brain.

The Amyloid Precursor Protein (APP) is infamous for its proposed pivotal role in the pathogenesis of Alzheimer's disease (AD). Much research on APP focusses on potential contributions to neurodegeneration, mostly based on mouse models with altered expression or mutated forms of APP. However, cumulative evidence from recent years indicates the indispensability of APP and its metabolites for normal brain physiology.

Two Sides of the Same Coin: A Case Report of First-Episode Catatonic Syndrome in a High-Functioning Autism Patient.

Catatonic phenomena such as stupor, mutism, stereotypy, echolalia, echopraxia, affective flattening, psychomotor deficits, and social withdrawal are characteristic symptoms of both schizophrenia and autism spectrum disorders (ASD), suggesting overlapping pathophysiological similarities such as altered glutamatergic and dopaminergic synaptic transmission and common genetic mutations. In daily clinical practice, ASD can be masked by manifest catatonic or psychotic symptoms and represent a diagnostic challenge, especially in patients with unknown or empty medical history. Unclear diagnosis is one of the main factors for delayed treatment.

Perinatal Hypoxia and Ischemia in Animal Models of Schizophrenia.

Intrauterine or perinatal complications constitute a major risk for psychiatric diseases. Infants who suffered from hypoxia-ischemia (HI) are at twofold risk to develop schizophrenia in later life. Several animal models attempt to reproduce these complications to study the yet unknown steps between an insult in early life and outbreak of the disease decades later.

Altered prepulse inhibition of the acoustic startle response in BDNF-deficient mice in a model of early postnatal hypoxia: implications for schizophrenia.

The brain-derived neurotrophic factor (BDNF) is a major proliferative agent in the nervous system. Both BDNF-deficiency and perinatal hypoxia represent genetic/environmental risk factors for schizophrenia. Moreover, a decreased BDNF response to birth hypoxia was associated with the disease.

Molecular and cellular dissection of NMDA receptor subtypes as antidepressant targets.

A growing body of evidence supports the idea that drugs targeting the glutamate system may represent a valuable therapeutic alternative in major depressive disorders (MDD). The rapid and prolonged mood elevating effect of the NMDA receptor (NMDAR) antagonist ketamine has been studied intensely. However, its clinical use is hampered by deleterious side-effects, such as psychosis.

APP as a Protective Factor in Acute Neuronal Insults.

Despite its key role in the molecular pathology of Alzheimer's disease (AD), the physiological function of amyloid precursor protein (APP) is unknown. Increasing evidence, however, points towards a neuroprotective role of this membrane protein in situations of metabolic stress. A key observation is the up-regulation of APP following acute (stroke, cardiac arrest) or chronic (cerebrovascular disease) hypoxic-ischemic conditions.

Amyloid Precursor Protein Protects Neuronal Network Function after Hypoxia via Control of Voltage-Gated Calcium Channels.

Unlabelled: Acute cerebral ischemia and chronic neurovascular diseases share various common mechanisms with neurodegenerative diseases, such as disturbed cellular calcium and energy homeostasis and accumulation of toxic metabolites. A link between these conditions may be constituted by amyloid precursor protein (APP), which plays a pivotal role in the pathogenesis of Alzheimer's disease, but has also been associated with the response to acute hypoxia and regulation of calcium homeostasis. We therefore studied hypoxia-induced loss of function and recovery upon reoxygenation in hippocampal slices of mice lacking APP (APP(-/-)) or selectively expressing its soluble extracellular domain (APPsα-KI).