---
_id: '6849'
abstract:
- lang: eng
  text: 'Brain function is mediated by complex dynamical interactions between excitatory
    and inhibitory cell types. The Cholecystokinin-expressing inhibitory cells (CCK-interneurons)
    are one of the least studied types, despite being suspected to play important
    roles in cognitive processes. We studied the network effects of optogenetic silencing
    of CCK-interneurons in the CA1 hippocampal area during exploration and sleep states.
    The cell firing pattern in response to light pulses allowed us to classify the
    recorded neurons in 5 classes, including disinhibited and non-responsive pyramidal
    cell and interneurons, and the inhibited interneurons corresponding to the CCK
    group. The light application, which inhibited the activity of CCK interneurons
    triggered wider changes in the firing dynamics of cells. We observed rate changes
    (i.e. remapping) of pyramidal cells during the exploration session in which the
    light was applied relative to the previous control session that was not restricted
    neither in time nor space to the light delivery. Also, the disinhibited pyramidal
    cells had higher increase in bursting than in single spike firing rate as a result
    of CCK silencing. In addition, the firing activity patterns during exploratory
    periods were more weakly reactivated in sleep for those periods in which CCK-interneuron
    were silenced than in the unaffected periods. Furthermore, light pulses during
    sleep disrupted the reactivation of recent waking patterns. Hence, silencing CCK
    neurons during exploration suppressed the reactivation of waking firing patterns
    in sleep and CCK interneuron activity was also required during sleep for the normal
    reactivation of waking patterns. These findings demonstrate the involvement of
    CCK cells in reactivation-related memory consolidation. An important part of our
    analysis was to test the relationship of the identified CCKinterneurons to brain
    oscillations. Our findings showed that these cells exhibited different oscillatory
    behaviour during anaesthesia and natural waking and sleep conditions. We showed
    that: 1) Contrary to the past studies performed under anaesthesia, the identified
    CCKinterneurons fired on the descending portion of the theta phase in waking exploration.
    2) CCKinterneuron preferred phases around the trough of gamma oscillations. 3)
    Contrary to anaesthesia conditions, the average firing rate of the CCK-interneurons
    increased around the peak activity of the sharp-wave ripple (SWR) events in natural
    sleep, which is congruent with new reports about their functional connectivity.
    We also found that light driven CCK-interneuron silencing altered the dynamics
    on the CA1 network oscillatory activity: 1) Pyramidal cells negatively shifted
    their preferred theta phases when the light was applied, while interneurons responses
    were less consistent. 2) As a population, pyramidal cells negatively shifted their
    preferred activity during gamma oscillations, albeit we did not find gamma modulation
    differences related to the light application when pyramidal cells were subdivided
    into the disinhibited and unaffected groups. 3) During the peak of SWR events,
    all but the CCK-interneurons had a reduction in their relative firing rate change
    during the light application as compared to the change observed at SWR initiation.
    Finally, regarding to the place field activity of the recorded pyramidal neurons,
    we showed that the disinhibited pyramidal cells had reduced place field similarity,
    coherence and spatial information, but only during the light application. The
    mechanisms behind such observed behaviours might involve eCB signalling and plastic
    changes in CCK-interneuron synapses. In conclusion, the observed changes related
    to the light-mediated silencing of CCKinterneurons have unravelled characteristics
    of this interneuron subpopulation that might change the understanding not only
    of their particular network interactions, but also of the current theories about
    the emergence of certain cognitive processes such as place coding needed for navigation
    or hippocampus-dependent memory consolidation. '
acknowledged_ssus:
- _id: Bio
- _id: PreCl
- _id: M-Shop
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Dámaris K
  full_name: Rangel Guerrero, Dámaris K
  id: 4871BCE6-F248-11E8-B48F-1D18A9856A87
  last_name: Rangel Guerrero
  orcid: 0000-0002-8602-4374
citation:
  ama: Rangel Guerrero DK. The role of CCK-interneurons in regulating hippocampal
    network dynamics. 2019. doi:<a href="https://doi.org/10.15479/AT:ISTA:6849">10.15479/AT:ISTA:6849</a>
  apa: Rangel Guerrero, D. K. (2019). <i>The role of CCK-interneurons in regulating
    hippocampal network dynamics</i>. Institute of Science and Technology Austria.
    <a href="https://doi.org/10.15479/AT:ISTA:6849">https://doi.org/10.15479/AT:ISTA:6849</a>
  chicago: Rangel Guerrero, Dámaris K. “The Role of CCK-Interneurons in Regulating
    Hippocampal Network Dynamics.” Institute of Science and Technology Austria, 2019.
    <a href="https://doi.org/10.15479/AT:ISTA:6849">https://doi.org/10.15479/AT:ISTA:6849</a>.
  ieee: D. K. Rangel Guerrero, “The role of CCK-interneurons in regulating hippocampal
    network dynamics,” Institute of Science and Technology Austria, 2019.
  ista: Rangel Guerrero DK. 2019. The role of CCK-interneurons in regulating hippocampal
    network dynamics. Institute of Science and Technology Austria.
  mla: Rangel Guerrero, Dámaris K. <i>The Role of CCK-Interneurons in Regulating Hippocampal
    Network Dynamics</i>. Institute of Science and Technology Austria, 2019, doi:<a
    href="https://doi.org/10.15479/AT:ISTA:6849">10.15479/AT:ISTA:6849</a>.
  short: D.K. Rangel Guerrero, The Role of CCK-Interneurons in Regulating Hippocampal
    Network Dynamics, Institute of Science and Technology Austria, 2019.
date_created: 2019-09-06T06:54:16Z
date_published: 2019-09-09T00:00:00Z
date_updated: 2023-09-19T10:01:12Z
day: '09'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: JoCs
doi: 10.15479/AT:ISTA:6849
file:
- access_level: closed
  checksum: 244dc4f74dbfc94f414156092298831f
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  creator: drangel
  date_created: 2019-09-09T13:09:45Z
  date_updated: 2021-02-10T23:30:09Z
  embargo_to: open_access
  file_id: '6865'
  file_name: Thesis_Damaris_Rangel_source.docx
  file_size: 18253100
  relation: source_file
- access_level: open_access
  checksum: 59c73be40eeaa1c4db24067270151555
  content_type: application/pdf
  creator: drangel
  date_created: 2019-09-09T13:09:52Z
  date_updated: 2020-09-11T22:30:04Z
  embargo: 2020-09-10
  file_id: '6866'
  file_name: Thesis_Damaris_Rangel_pdfa.pdf
  file_size: 2160109
  relation: main_file
  request_a_copy: 0
file_date_updated: 2021-02-10T23:30:09Z
has_accepted_license: '1'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Published Version
page: '97'
publication_identifier:
  isbn:
  - '9783990780039'
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '5914'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Jozsef L
  full_name: Csicsvari, Jozsef L
  id: 3FA14672-F248-11E8-B48F-1D18A9856A87
  last_name: Csicsvari
  orcid: 0000-0002-5193-4036
title: The role of CCK-interneurons in regulating hippocampal network dynamics
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...