Modular, cement-free, customized headpost and connector-chamber implants for macaques.
Chronic implants
Connector chamber
Headpost
Macaque
Osseointegration
Refinement
Journal
Journal of neuroscience methods
ISSN: 1872-678X
Titre abrégé: J Neurosci Methods
Pays: Netherlands
ID NLM: 7905558
Informations de publication
Date de publication:
01 06 2023
01 06 2023
Historique:
received:
09
11
2022
revised:
15
05
2023
accepted:
20
05
2023
medline:
14
6
2023
pubmed:
26
5
2023
entrez:
25
5
2023
Statut:
ppublish
Résumé
Neurophysiological studies with awake macaques typically require chronic cranial implants. Headpost and connector-chamber implants are used to allow head stabilization and to house connectors of chronically implanted electrodes, respectively. We present long-lasting, modular, cement-free headpost implants made of titanium that consist of two pieces: a baseplate and a top part. The baseplate is implanted first, covered by muscle and skin and allowed to heal and osseointegrate for several weeks to months. The percutaneous part is added in a second, brief surgery. Using a punch tool, a perfectly round skin cut is achieved providing a tight fit around the implant without any sutures. We describe the design, planning and production of manually bent and CNC-milled baseplates. We also developed a remote headposting technique that increases handling safety. Finally, we present a modular, footless connector chamber that is implanted in a similar two-step approach and achieves a minimized footprint on the skull. Twelve adult male macaques were successfully implanted with a headpost and one with the connector chamber. To date, we report no implant failure, great headpost stability and implant condition, in four cases even more than 9 years post-implantation. The methods presented here build on several related previous methods and provide additional refinements to further increase implant longevity and handling safety. Optimized implants can remain stable and healthy for at least 9 years and thereby exceed the typical experiment durations. This minimizes implant-related complications and corrective surgeries and thereby significantly improves animal welfare.
Sections du résumé
BACKGROUND
Neurophysiological studies with awake macaques typically require chronic cranial implants. Headpost and connector-chamber implants are used to allow head stabilization and to house connectors of chronically implanted electrodes, respectively.
NEW METHOD
We present long-lasting, modular, cement-free headpost implants made of titanium that consist of two pieces: a baseplate and a top part. The baseplate is implanted first, covered by muscle and skin and allowed to heal and osseointegrate for several weeks to months. The percutaneous part is added in a second, brief surgery. Using a punch tool, a perfectly round skin cut is achieved providing a tight fit around the implant without any sutures. We describe the design, planning and production of manually bent and CNC-milled baseplates. We also developed a remote headposting technique that increases handling safety. Finally, we present a modular, footless connector chamber that is implanted in a similar two-step approach and achieves a minimized footprint on the skull.
RESULTS
Twelve adult male macaques were successfully implanted with a headpost and one with the connector chamber. To date, we report no implant failure, great headpost stability and implant condition, in four cases even more than 9 years post-implantation.
COMPARISON WITH EXISTING METHODS
The methods presented here build on several related previous methods and provide additional refinements to further increase implant longevity and handling safety.
CONCLUSIONS
Optimized implants can remain stable and healthy for at least 9 years and thereby exceed the typical experiment durations. This minimizes implant-related complications and corrective surgeries and thereby significantly improves animal welfare.
Identifiants
pubmed: 37230259
pii: S0165-0270(23)00118-8
doi: 10.1016/j.jneumeth.2023.109899
pii:
doi:
Substances chimiques
Titanium
D1JT611TNE
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
109899Informations de copyright
Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of Competing Interest P.F. has a patent on thin-film electrodes (US20170181707A1) and is beneficiary of a respective license contract with Blackrock Microsystems LLC (Salt Lake City, UT). P.F. is member of the Advisory Board of CorTec GmbH (Freiburg, Germany). The authors declare no further competing interests.