Browsing by Subject "HABITUATION"

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  • Morello, Francesca; Voikar, Vootele; Parkkinen, Pihla; Panhelainen, Anne; Rosenholm, Marko; Makkonen, Aki; Rantamäki, Tomi; Piepponen, Petteri; Aitta-aho, Teemu; Partanen, Juha (2020)
    The neural circuits regulating motivation and movement include midbrain dopaminergic neurons and associated inhibitory GABAergic and excitatory glutamatergic neurons in the anterior brainstem. Differentiation of specific subtypes of GABAergic and glutamatergic neurons in the mouse embryonic brainstem is controlled by a transcription factorTal1. This study characterizes the behavioral and neurochemical changes caused by the absence ofTal1function. TheTal1(cko)mutant mice are hyperactive, impulsive, hypersensitive to reward, have learning deficits and a habituation defect in a novel environment. Only minor changes in their dopaminergic system were detected. Amphetamine induced striatal dopamine release and amphetamine induced place preference were normal inTal1(cko)mice. Increased dopamine signaling failed to stimulate the locomotor activity of theTal1(cko)mice, but instead alleviated their hyperactivity. Altogether, theTal1(cko)mice recapitulate many features of the attention and hyperactivity disorders, suggesting a role forTal1regulated developmental pathways and neural structures in the control of motivation and movement.
  • Annanmaki, Tua; Palmu, Kirsi; Murros, Kari; Partanen, Juhani (2017)
    The diagnosis of cognitive impairment and dementia often occurring with Parkinson's disease (PD) is still based on the clinical picture and neuropsychological examination. Ancillary methods to detect cognitive decline in these patients are, therefore, needed. Alterations in the latencies and amplitudes of evoked response potential (ERP) components N100 and P200 have been described in PD. Due to limited number of studies their relation to cognitive deficits in PD remains obscure. The present study was designed to examine if alterations in the N100- and P200-potentials associate with neuropsychological impairment in PD. EEG-ERP was conducted to 18 PD patients and 24 healthy controls. The patients underwent a thorough neuropsychological evaluation. The controls were screened for cognitive impairment with Consortium to Establish Alzheimer's disease (CERAD)-testing and a normal result were required to be included in the study. The N100-latency was prolonged in the patients compared to the controls (p = 0.05). In the patients, the N100 latency correlated significantly with a visual working memory task (p = 0.01). Also N100 latency was prolonged and N100 amplitude habituation diminished in the patients achieving poorly in this task. We conclude that prolonged N100-latency and diminished amplitude habituation associate with visual working memory impairment in PD.
  • Moen, Gro Kvelprud; Ordiz, Andres; Kindberg, Jonas; Swenson, Jon E.; Sundell, Janne; Stoen, Ole-Gunnar (2019)
    Human disturbance causes behavioral responses in wildlife, including large carnivores. Previous research in Scandinavia has documented that brown bears (Ursus arctos) show a variety of behavioral reactions to different human activities. We investigated how proximity to human settlements and roads, as proxies of human influence, affected brown bears' reactions to encountering humans. We analyzed experimental approaches to GPS collared bears, 18 males and 23 single females, in Sweden (n = 148 approaches) and Finland (n = 33), conducted between 2004 and 2012. The bears in Finland inhabited areas with higher human density compared to Sweden. However, the proportion of bears staying or moving when approached and the flight initiation distances were similar in both countries. In Sweden, the flight responses were not dependent on human densities or roads inside the bears' home ranges or the distances from the bears to roads and settlements. Brown bears in Fennoscandia live in areas with relatively low human population densities, but in many areas with high forestry road densities. Our results show that bears' flight reactions were consistent between areas, which is an important message for management, reinforcing previous studies that have documented human avoidance by bears at different spatial and temporal scales.
  • Nuuttila, Simo; Eklund, Mikael; Joutsa, Juho; Jaakkola, Elina; Mäkinen, Elina; Honkanen, Emma A.; Lindholm, Kari; Noponen, Tommi; Ihalainen, Toni; Murtomäki, Kirsi; Nojonen, Tanja; Levo, Reeta; Mertsalmi, Tuomas; Scheperjans, Filip; Kaasinen, Valtteri (2021)
    Glabellar tap or reflex (GR) is an old bedside clinical test used in the diagnostics of Parkinson's disease (PD), but its diagnostic value is unclear. This study examines the diagnostic validity and reliability of GR in PD in relation to brain dopaminergic activity. GR was performed on 161 patients with PD, 47 patients with essential tremor (ET) and 40 healthy controls immediately prior to dopamine transporter (DAT) [I-123]FP-CIT SPECT scanning. The binding ratios were investigated with consideration of the GR result (normal/abnormal). In addition, the consistency of the GR was investigated with 89 patients after a mean follow-up of 2.2 years. PD and ET patients had higher GR scores than healthy controls (p < 0.001), but there was no difference in GR between PD and ET patients (p = 0.09). There were no differences in the ratio of abnormal to normal GRs between the PD and ET groups (73% vs. 64% abnormal, respectively, p = 0.13) or in DAT binding between PD patients with abnormal and normal GRs (p > 0.36). Over follow-up, the GR changed from abnormal to normal in 20% of PD patients despite the presence of clinically typical disease. The sensitivity and specificity of GR for differentiating PD from ET were 78.3% and 36.2%, respectively. Although GR has been used by clinicians in the diagnostics of PD, it does not separate PD from ET. It also shows considerable inconsistency over time, and abnormal GR has no relationship with dopamine loss. Its usefulness should be tested for other clinical diagnostic purposes.