D Methods and Applications O N Electric current O Magnetic - - PowerPoint PPT Presentation

▶
d
SMART_READER_LITE
LIVE PREVIEW

D Methods and Applications O N Electric current O Magnetic - - PowerPoint PPT Presentation

Mar 07, 2023 162 likes •829 views

TMS in animal models: D Methods and Applications O N Electric current O Magnetic field Electric Coil T field C O P Y Alexander Rotenberg, M.D., Ph.D. Director, Neuromodulation Program Boston Childrens Hospital Conflict of

slide-1
SLIDE 1

TMS in animal models: Methods and Applications

Alexander Rotenberg, M.D., Ph.D. Director, Neuromodulation Program Boston Children’s Hospital

Coil Electric field Magnetic field Electric current

D O N O T C O P Y

slide-2
SLIDE 2

Conflict of Interest Disclosure

Current:

Neuro’motion Inc. (technology for improving emotional control; co-founder) NeuroRex (medical advisor) Brainsway Inc. (research support [equipment and personnel]) Soterix Medical Inc. (research support [equipment]) Neuroelectrics Inc. (research support [equipment]) Journal of Central Nervous System Diseases (EIC) NIH NIMH, DoD, CIMIT, ERF, TRP (research grants)

Past:

Neuropace Inc. (research grant and equipment) Nexstim Inc. (consultant) Sage Therapeutics Inc. (consultant) Fisher Family Fund and Fisher-Wallace Inc. (research support [unrestricted gift and equipment])

Alexander Rotenberg

D O N O T C O P Y

slide-3
SLIDE 3

TMS in animals

D O N O T C O P Y

slide-4
SLIDE 4

Why TMS studies in animals?

– Basic Science – Translational Research

Poma et al., 2006

D O N O T C O P Y

slide-5
SLIDE 5

Advantages of animal subject

  • Subject homogeneity
  • Available histology
  • Genetic / disease models

Liebetanz et al., 2003

D O N O T C O P Y

slide-6
SLIDE 6

Translational Relevance

  • Disease modeling
  • TMS safety
  • Neuronal connectivity
  • Synaptic plasticity
  • Cortical organization

Charlet de Sauvage et al. 2007

D O N O T C O P Y

slide-7
SLIDE 7

Induced dysfunction: neglect-like syndrome in cats

Valero Cabre et al., 2005

D O N O T C O P Y

slide-8
SLIDE 8

Frequency-Dependent 14C-2DG uptake modulated in cat

Valero-Cabre et al. 2006 20 Hz off-line 20 Hz on-line 1 Hz on-line

D O N O T C O P Y

slide-9
SLIDE 9

No injury after prolonged TMS

  • Counter, 1995:

– No deleterious effect on AEP after 1000 pulses at 1Hz n rabbits

  • Nishikiori, 1996:

– No cortical or brainstem lesions after ~1 month of daily TMS in rabbits

  • Liebetanz et al., 2003:

– No MRS or histologic changes after 5 days of 1 Hz rTMS

  • Charlet de Sauvage et al., 2007

– No DNA damage after 2000 TMS pulses

D O N O T C O P Y

slide-10
SLIDE 10

Most translational research is with rodents

  • Well-described disease models
  • Inexpensive
  • Experiments may be translated to clinical care
  • TMS effect can be examined at multiple levels:

whole animal, brain slice, single cell, etc.

Kistsen et al., in progress

D O N O T C O P Y

slide-11
SLIDE 11

Disadvantages of rat model

– Compromised stimulus focality – Slightly more difficult EEG – Required restraint or anesthesia

Luft et al., 2001 Kamida et al., 1998

D O N O T C O P Y

slide-12
SLIDE 12

Stimulation protocols

Frye, Rotenberg, et al. Child Neurol 2007

D O N O T C O P Y

slide-13
SLIDE 13

Off-Center Coil

Rotenberg et al., 2009 EMG EMG Ground

D O N O T C O P Y

slide-14
SLIDE 14

Lateralized brachioradialis MEP

D O N O T C O P Y

slide-15
SLIDE 15

Lateralized TMS in Rats

D O N O T C O P Y

slide-16
SLIDE 16

Stimulation protocols

Frye, Rotenberg, et al. Child Neurol 2007

D O N O T C O P Y

slide-17
SLIDE 17

1

Conditioning TMS 2 Test TMS Control SICI; 2 ms ISI ICF; 12 ms ISI

0.5 mV 25 ms

LICI; 200 ms ISI

0.5 mV 50 ms

Rotenberg and Pascual-Leone, 2010

Measures of Cortical Excitability by Paired-Pulse TMS (ppTMS)

D O N O T C O P Y

slide-18
SLIDE 18

Paired-Pulse Inhibition in rats

Vahabzadeh et al., 2011

D O N O T C O P Y

slide-19
SLIDE 19

Inhibition in rats preserved with anesthesia

Vahabzadeh et al., 2011

D O N O T C O P Y

slide-20
SLIDE 20

Inhibition lost with GABA-A antagonist / seizures

Vahabzadeh et al., 2011

D O N O T C O P Y

slide-21
SLIDE 21

A B

PTZ Effects on MEP Inhibition by ppTMS

D O N O T C O P Y

slide-22
SLIDE 22

MMG (Mechanomyography)

Detection of cortical inhibition by MMG and ppTMS in unanesthetized rats

Accelerometer

D O N O T C O P Y

slide-23
SLIDE 23

EMG v.s MMG

MMG (V)

  • 0.15
  • 0.10
  • 0.05

0.00 0.05 0.10 0.15 50ms

60%MO 70%MO 80%MO 90%MO 100%MO

MMG

Input–output curve of MMG

EMG (Tibia anterior m.)

D O N O T C O P Y

slide-24
SLIDE 24

MMG testing during TMS

Awake rat

D O N O T C O P Y

slide-25
SLIDE 25
  • reduced inhibition with PTZ and increased inhibition with PB

GABAA-mediated cortical inhibition following pentobarbital (PB) and pentylenetetrazole (PTZ)

200ms ISI

Condition

Pre P10 P60 Pre P10 P60 Pre P10 P60

% of unconditioned MMG

20 40 60 80 Saline PB PTZ

Left Right Ave (L+R)

*** * *** * *** *

D O N O T C O P Y

slide-26
SLIDE 26

TMS in Experimental Epilepsy

  • Diagnostic

– Measure of cortical excitability – Assessment of drug (or other intervention) effect

  • Therapeutic

– Anticonvulsant (seizure termination) – Antiepileptic (seizure prevention)

D O N O T C O P Y

slide-27
SLIDE 27

Fluid Percussion Injury: a post-traumatic epilepsy model

Nature Protocols, 2011 McIntosh et al., 1989

D O N O T C O P Y

slide-28
SLIDE 28
  • Rats with TBI show less ppTMS-MMG inhibition relative to

sham-TBI controls 6 weeks after injury, when post-traumatic epilepsy develops.

Reduced cortical inhibition in TBI: a marker for epileptogenesis?

50ms ISI

L R L R L R

% of unconditioned MMG

20 40 60 80 100 120 Normal rats Chronic TBI rats

100ms ISI 200ms ISI

** * * *

2mm

D O N O T C O P Y

slide-29
SLIDE 29

 Gradual decrease in LICI reaches significance at 1 week after TBI as compared to pre-values. More detailed data compared between sham and TBI group in LICI at 100 ms (C) and 200 ms ISI (D) following TBI. (*p<0.05, **p<0.01)

100ms ISI

Time

Pre 1WK 2WKS 3WKS 4WKS 5WKS 6WKS

Ratio

0.0 0.2 0.4 0.6 0.8 1.0 Sham control TBI

** * * *

200ms ISI

Time

Pre 1WK 2WKS 3WKS 4WKS 5WKS 6WKS

Ratio

0.0 0.2 0.4 0.6 0.8 1.0 Sham control TBI

** * * * * * Hsieh et al., ECCN 2011 abstr.

Loss of cortical inhibition after TBI

D O N O T C O P Y

slide-30
SLIDE 30

4 2 Sham control TBI (lesion) 4 2 6 6

NeuN

4 2 TBI (contra-lesion) 6 I II/III V VI

General cortical architecture was not affected by TBI

Layer V thickness NeuN

D O N O T C O P Y

slide-31
SLIDE 31

Gonchar et al., 2007, Front Neuroanat.

Parvalbumin (PV) interneurons are the major sub-type of cortical inhibitory neuron… and vulnerable to oxidative stress

D O N O T C O P Y

slide-32
SLIDE 32

4 2 Sham control Post-TBI (peri-lesion) 4 2 6 6

PV

4 2 Post-TBI (contra-lesion) 6 I II/III V VI * *** *** * n.s. n.s. Peri-lesion Contra-lesion

Gradual loss of parvalbumin (PV)-cells after TBI

D O N O T C O P Y

slide-33
SLIDE 33

8-oxo-dG

I II/III V VI 4 2 Sham control Post-TBI (peri-lesion) 4 2 6 6 4 2 Post-TBI (contra-lesion) 6

n.s. *** *** ** n.s. n.s. Peri-lesion Contra-lesion

Delayed increase in oxidative stress after TBI

D O N O T C O P Y

slide-34
SLIDE 34

Implications for Therapy TBI Epileptic seizure PTE

Antioxidant (N-acetylcysteine) Oxidative stress Loss of PV-cells ↓ Perineuronal nets ↓ Otx2 Impaired inhibition Neuroprotection (Otx2) Lee et al., 2013

D O N O T C O P Y

slide-35
SLIDE 35

D O N O T C O P Y

slide-36
SLIDE 36

Ceftriaxone treatment prophylaxes against posttraumatic seizures

D O N O T C O P Y

slide-37
SLIDE 37

ppTMS as a biomarker in TBI treatment

ppTMS-MMG at 200ms ISI

Time

Pre 1W 2W 3W 4W 5W 6W

Ratio of unconditioned MMG

0.0 0.2 0.4 0.6 0.8 1.0 1.2 Saline CTX

n=7 (saline) n=7 (CTX)

n=3 (saline) n=3 (CTX)

p=0.07 p=0.04 p=0.05 p=0.002

n=7 (saline) n=6 (CTX)

Hameed et al., 2014

D O N O T C O P Y

slide-38
SLIDE 38

Stimulation protocols

Frye, Rotenberg, et al. Child Neurol 2007

D O N O T C O P Y

slide-39
SLIDE 39

Therapeutic TMS

  • Three potential targets:

– Seizure – Epilepsy – Epileptogenesis

D O N O T C O P Y

slide-40
SLIDE 40

Rat TMS-EEG methods

Rotenberg, et al., 2005 Ives et al., 2006 EKG EEG

D O N O T C O P Y

slide-41
SLIDE 41

Spike Provocation by TMS in Rats

Rotenberg, Brain Topogr 2010

D O N O T C O P Y

slide-42
SLIDE 42

Rat “deep” TMS during seizure

EEG analysis (seizure detection) coil electric current magnetic field electric field torso strap restraints

D O N O T C O P Y

slide-43
SLIDE 43

Kainate (KA) Model Status Epilepticus

  • Three-Stage Effect:

– Acute 2-3 hour prolonged seizure – Subacute 6-9 week seizure-free period – Chronic daily recurrent seizures

D O N O T C O P Y

slide-44
SLIDE 44

Terminated KA seizure

Ives, Rotenberg et al., Clin Neurophys2006

D O N O T C O P Y

slide-45
SLIDE 45

Refractory KA Seizure

5 sec

D O N O T C O P Y

slide-46
SLIDE 46

rTMS during KA seizure

Rotenberg et al., Clin Neurophys 2008

D O N O T C O P Y

slide-47
SLIDE 47

rTMS during KA seizures

Relative Average Seizure Duration (% untreated control) 0.25 Hz

0% 25% 50% 75% 100% 125% 150%

0.5 Hz

*

0.75 Hz

untreated sham active

*

untreated sham active untreated sham active

Rotenberg et al., 2008

D O N O T C O P Y

slide-48
SLIDE 48

Reduced c-Fos expression (and excitotoxicity?) with 0.5 Hz rTMS

KA only Control KA + TMS Rotenberg et al., AES abstr 2005

D O N O T C O P Y

slide-49
SLIDE 49

Mixed results in controlled trials

– Theodore et al., Neurology 2002

  • N=24; 1 Hz X 900 BID X 1 week
  • Mild and short-lived seizure reduction

– Fregni et al., Annal Neurol 2006

  • N=21; 1 Hz X 1200 X 5 days
  • Significant seizure reduction and EEG improvement

– Cantello et al., Epilepsia 2007

  • N=43; 0.3 Hz X 1000 X 5 days
  • Significant EEG improvement; no change in seizures

– Sun et al., Epilepsia 2012

  • N=64; 0.5 Hz X 1500 X 14 days
  • Significant seizure reduction and EEG improvement

D O N O T C O P Y

slide-50
SLIDE 50

Better effect with 1 Hz

.3 .5 1

  • 1
  • 5

5 1 1 5 c h a n g e H z

Rotenberg et al., unpublished data % reduction in Seizure Frequency After rTMS

D O N O T C O P Y

slide-51
SLIDE 51

Frequency-response in vitro LTD approximates rTMS data

Nakano et al., 2004

D O N O T C O P Y

slide-52
SLIDE 52

Molecular Basis: Does rTMS induce LTP/LTD?

Kandel, 2001

D O N O T C O P Y

slide-53
SLIDE 53

Kandel, 2001

rTMS mechanisms

D O N O T C O P Y

slide-54
SLIDE 54

Muller et al., PLOS One 2014

*

1 0.5 0.25 S1 S0.5 S0.25

Stimulation Condition (Hz)

MEP depression by rTMS in anesthetized rat

D O N O T C O P Y

slide-55
SLIDE 55

Kandel, 2001

rTMS mechanisms

D O N O T C O P Y

slide-56
SLIDE 56

CREB phosphorylation by 20 Hz rTMS

0% 50% 100% 150% 200% 250% 300%

20 Hz rTMS Sham

pCREB (% control) 20 Hz rTMS Sham

D O N O T C O P Y

slide-57
SLIDE 57

Kandel, 2001

rTMS mechanisms

D O N O T C O P Y

slide-58
SLIDE 58

BDNF expression after rTMS

anesthetized awake Gersner et al., J. Neursci 2011

D O N O T C O P Y

slide-59
SLIDE 59

Gersner et al., J. Neursci 2011

GluR1 expression and phosphorylation after rTMS

D O N O T C O P Y

slide-60
SLIDE 60

D O N O T C O P Y

slide-61
SLIDE 61

Follow-up

Work in Progress: Time (min)

10 20 30

  • 10

Baseline Anesthesia Kainic acid injection rTMS/Sham

  • 70
  • 85

Lorazepam Follow-up Sham/rTMS /Lorazepam

Gap in knowledge: how to combine neurostimulation with AEDS?

D O N O T C O P Y

slide-62
SLIDE 62

Spike suppression by 20 Hz rTMS

A

Sham rTMS 30 sec Baseline Treatment Follow-up

0.5 1 1.5 2 2.5 Baseline Treatment Follow-up Normalized spike frequency (auto-count)

Baseline Treatment Follow-up

*** **

B C

Time (sec)

* *

D O N O T C O P Y

slide-63
SLIDE 63

The effect of Lorazepam and rTMS combination treatment on spike frequency LZP + Sham LZP + LZP LZP + rTMS 2nd treatment Baseline LZP Follow-up 30 sec

0.2 0.4 0.6 0.8 1 1.2 1.4 BL 1st 2nd FU Normalized spike frequency (auto-count)

Baseline LZP Follow-up 2nd Treatment

** ***

D O N O T C O P Y

slide-64
SLIDE 64

Can we model TMs in rodents without magnetic coils?

Hsieh et al., work in progress

D O N O T C O P Y

slide-65
SLIDE 65

LTP-like potentiation after electrical iTBS

Hsieh et al., work in progress

D O N O T C O P Y

slide-66
SLIDE 66

D O N O T C O P Y