scholarly journals Tolerance to neurochemical and behavioral effects of the hallucinogen 25I-NBOMe

2021 ◽  
Author(s):  
Monika Herian ◽  
Mateusz Skawski ◽  
Adam Wojtas ◽  
Małgorzata K. Sobocińska ◽  
Karolina Noworyta ◽  
...  
Keyword(s):  
Short Term Memory ◽  
Day Treatment ◽  
Glutamate Release ◽  
Chronic Administration ◽  
Brain Regions ◽  
Acute Administration ◽  
Challenge Dose ◽  
Short Term ◽  
Term Memory ◽  
Acute Dose

Abstract Rationale 4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is a potent serotonin 5-HT2A/2C receptor agonist with hallucinogenic activity. There is no data on the 25I-NBOMe effect on brain neurotransmission and animal performance after chronic administration. Objectives We examined the effect of a 7-day treatment with 25I-NBOMe (0.3 mg/kg/day) on neurotransmitters’ release and rats’ behavior in comparison to acute dose. Methods Changes in dopamine (DA), serotonin (5-HT), acetylcholine (ACh), and glutamate release were studied using microdialysis in freely moving rats. The hallucinogenic activity was measured in the wet dog shake (WDS) test. The animal locomotion was examined in the open field (OF) test, short-term memory in the novel object recognition (NOR) test. The anxiogenic/anxiolytic properties of the drug were tested using the light/dark box (LDB) test. Results Repeated administration of 25I-NBOMe decreased the response to a challenge dose of DA, 5-HT, and glutamatergic neurons in the frontal cortex as well as weakened the hallucinogenic activity in comparison to acute dose. In contrast, striatal and accumbal DA and 5-HT release and accumbal but not striatal glutamate release in response to the challenge dose of 25I-NBOMe was increased in comparison to acute treatment. The ACh release was increased in all brain regions. Behavioral tests showed a motor activity reduction and memory deficiency in comparison to a single dose and induction of anxiety after the drug’s chronic and acute administration. Conclusions Our findings suggest that multiple injections of 25I-NBOMe induce tolerance to hallucinogenic activity and produce alterations in neurotransmission. 25I-NBOMe effect on short-term memory, locomotor function, and anxiety seems to be the result of complex interactions between neurotransmitter pathways.

scholarly journals A shared representation of order between encoding and recognition in visual short-term memory

2016 ◽  
Author(s):  
Kristjan Kalm ◽  
Dennis Norris
Keyword(s):  
Short Term Memory ◽  
Activity Patterns ◽  
Positional Information ◽  
Brain Regions ◽  
Order Information ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Recognition Phase ◽  
The Individual

AbstractMost complex tasks require people to bind individual stimuli into a sequence in short term memory (STM). For this purpose information about the order of the individual stimuli in the sequence needs to be in active and accessible form in STM over a period of few seconds. Here we investigated how the temporal order information is shared between the presentation and response phases of an STM task. We trained a classification algorithm on the fMRI activity patterns from the presentation phase of the STM task to predict the order of the items during the subsequent recognition phase. While voxels in a number of brain regions represented positional information during either presentation and recognition phases, only voxels in the lateral prefrontal cortex (PFC) and the anterior temporal lobe (ATL) represented position consistently across task phases. A shared positional code in the ATL might reflect verbal recoding of visual sequences to facilitate the maintenance of order information over several seconds.

scholarly journals Does sustained ERP activity in posterior lexico-semantic processing areas during short-term memory tasks only reflect activated long-term memory?

2003 ◽  
Vol 26 (6) ◽  
pp. 746-747 ◽  
Author(s):  
Steve Majerus ◽  
Martial Van der Linden ◽  
Fabienne Collette ◽  
Eric Salmon
Keyword(s):  
Semantic Processing ◽  
Short Term Memory ◽  
Brain Regions ◽  
Active Part ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Rule Out

We challenge Ruchkin et al.'s claim in reducing short-term memory (STM) to the active part of long-term memory (LTM), by showing that their data cannot rule out the possibility that activation of posterior brain regions could also reflect the contribution of a verbal STM buffer.

Expectations impact short-term memory through changes in connectivity between attention- and task-related brain regions

Cortex ◽  
2016 ◽  
Vol 78 ◽  
pp. 1-14 ◽  
Author(s):  
Christopher Sinke ◽  
Katarina Forkmann ◽  
Katharina Schmidt ◽  
Katja Wiech ◽  
Ulrike Bingel
Keyword(s):  
Short Term Memory ◽  
Brain Regions ◽  
Short Term ◽  
Term Memory ◽  
And Task

scholarly journals The neural basis of precise visual short-term memory for complex recognisable objects

2016 ◽  
Author(s):  
Michele Veldsman ◽  
Daniel J. Mitchell ◽  
Rhodri Cusack
Keyword(s):  
Short Term Memory ◽  
Brain Regions ◽  
Core Network ◽  
Neural Basis ◽  
Short Term ◽  
Term Memory ◽  
Photographic Images ◽  
Visual Short Term Memory ◽  
Stimulus Generation ◽  
The Impact

AbstractRecent evidence suggests that visual short-term memory (VSTM) capacity estimated using simple objects, such as colours and oriented bars, may not generalise well to more naturalistic stimuli. More visual detail can be stored in VSTM when complex, recognisable objects are maintained compared to simple objects. It is not yet known if it is recognisability that enhances memory precision, nor whether maintenance of recognisable objects is achieved with the same network of brain regions supporting maintenance of simple objects.We used a novel stimulus generation method to parametrically warp photographic images along a continuum, allowing separate estimation of the precision of memory representations and the number of items retained. The stimulus generation method was also designed to create unrecognisable, though perceptually matched, stimuli, to investigate the impact of recognisability on VSTM. We adapted the widely-used change detection and continuous report paradigms for use with complex, photographic images.Across three functional magnetic resonance imaging (fMRI) experiments, we demonstrated greater precision for recognisable objects in VSTM compared to unrecognisable objects. This clear behavioural advantage was not the result of recruitment of additional brain regions, or of stronger mean activity within the core network. Representational similarity analysis revealed greater variability across item repetitions in the representations of recognisable, compared to unrecognisable complex objects. We therefore propose that a richer range of neural representations support VSTM for complex recognisable objects.

scholarly journals Altered connectivity among emotion-related brain regions during short-term memory in Alzheimer's disease

2010 ◽  
Vol 31 (5) ◽  
pp. 780-786 ◽  
Author(s):  
R. Shayna Rosenbaum ◽  
Maura L. Furey ◽  
Barry Horwitz ◽  
Cheryl L. Grady
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Short Term Memory ◽  
Brain Regions ◽  
Short Term ◽  
Term Memory

The short-term dynamics within a network of connections is creative

2003 ◽  
Vol 26 (6) ◽  
pp. 752-753
Author(s):  
William A. Phillips
Keyword(s):  
Short Term Memory ◽  
Brain Regions ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Sensory Storage

Although visual long-term memory (VLTM) and visual short-term memory (VSTM) can be distinguished from each other (and from visual sensory storage [SS]), they are embodied within the same modality-specific brain regions, but in very different ways: VLTM as patterns of connectivity and VSTM as patterns of activity. Perception and VSTM do not “activate” VLTM. They use VLTM to create novel patterns of activity relevant to novel circumstances.

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