Effects of Atomoxetine on Motor and Cognitive Behaviors and Brain Electrophysiological Activity of Dopamine Transporter Knockout Rats

Pharmacological Modulation of Cognitive Test Solution in Mice of Two Genotypes

Mice of two strains selected for successful solution of "object permanence" test and for lack of such solution demonstrated the differential reaction to injections of two drugs. The effects of injections of atomoxetine. which blocks the noradrenaline reuptake, and of 'non-benzodiazepine" anxiolytic afobazol was different. The success of solutions increased in mice selected for this test "non-solution": and decreased or was inefficient in mice, selected for successful solution of object permanence cognitive test.

Pre-Pulse Inhibition of an escape response in adult fruit fly, Drosophila melanogaster

Pre-Pulse Inhibition (PPI) is a neural process where suppression of a startle response is elicited by preceding the startling stimulus (Pulse) with a weak, non-startling one (Pre-Pulse). Defective PPI is widely employed as a behavioural endophenotype in humans and mammalian disorder-relevant models for neuropsychiatric disorders. We have developed a user-friendly, semi-automated, high-throughput-compatible Drosophila light-off jump response PPI paradigm, with which we demonstrate that PPI, with similar parameters measured in mammals, exists in adults of this model organism. We report that Drosophila PPI is affected by reduced expression of Dysbindin and both reduced and increased expression of Nmdar1 (N-methyl-D-aspartate receptor 1), perturbations associated with schizophrenia. Studying the biology of PPI in an organism that offers a plethora of genetic tools and a complex and well characterized connectome will greatly facilitate our efforts to gain deeper insight into the aetiology of human mental disorders, while reducing the need for mammalian models.

A Custom Solution for Acoustic Startle Response Setup with Spike2-Based Data Acquisition Interface

This article presents a low-cost and flexible software solution for acoustic startle response (ASR) test that can be used with a Spike2-based interface. ASR is a reflexive response to an unexpected, loud acoustic stimulus, and prepulse inhibition (PPI) is a phenomenon in which the startle response is reduced when preceded by a weak prestimulus of the same modality. Measuring PPI is important because changes in PPI have been observed in patients with various psychiatric and neurological disorders. Commercial ASR testing systems are expensive, and their closed source code affects their transparency and result reproducibility. The proposed software is easy to install and use. The Spike2 script is customizable and supports a wide range of PPI protocols. As an example of PPI recording, the article presents data obtained in female rats, both wild-type (WT) and dopamine transporter knockout (DAT-KO), showing the same tendency as the data obtained in males, with ASR on a single pulse higher than ASR on prepulse+pulse, and PPI reduced in DAT-KO rats compared to WT.

Dopamine Transporter Deficient Rodents: Perspectives and Limitations for Neuroscience

The key element of dopamine (DA) neurotransmission is undoubtedly DA transporter (DAT), a transmembrane protein responsible for the synaptic reuptake of the mediator. Changes in DAT's function can be a key mechanism of pathological conditions associated with hyperdopaminergia. The first strain of gene-modified rodents with a lack of DAT were created more than 25 years ago. Such animals are characterized by increased levels of striatal DA, resulting in locomotor hyperactivity, increased levels of motor stereotypes, cognitive deficits, and other behavioral abnormalities. The administration of dopaminergic and pharmacological agents affecting other neurotransmitter systems can mitigate those abnormalities. The main purpose of this review is to systematize and analyze (1) known data on the consequences of changes in DAT expression in experimental animals, (2) results of pharmacological studies in these animals, and (3) to estimate the validity of animals lacking DAT as models for discovering new treatments of DA-related disorders.

Noradrenergic Modulation of Learned and Innate Behaviors in Dopamine Transporter Knockout Rats by Guanfacine

Investigation of the precise mechanisms of attention deficit and hyperactivity disorder (ADHD) and other dopamine-associated conditions is crucial for the development of new treatment approaches. In this study, we assessed the effects of repeated and acute administration of α2A-adrenoceptor agonist guanfacine on innate and learned forms of behavior of dopamine transporter knockout (DAT-KO) rats to evaluate the possible noradrenergic modulation of behavioral deficits. DAT-KO and wild type rats were trained in the Hebb-Williams maze to perform spatial working memory tasks. Innate behavior was evaluated via pre pulse inhibition (PPI). Brain activity of the prefrontal cortex and the striatum was assessed. Repeated administration of GF improved the spatial working memory task fulfillment and PPI in DAT-KO rats, and led to specific changes in the power spectra and coherence of brain activity. Our data indicate that both repeated and acute treatment with a non-stimulant noradrenergic drug lead to improvements in the behavior of DAT-KO rats. This study further supports the role of the intricate balance of norepinephrine and dopamine in the regulation of attention. The observed compensatory effect of guanfacine on the behavior of hyperdopaminergic rats may be used in the development of combined treatments to support the dopamine-norepinephrine balance.