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Colony-Wide Analysis of Mouse Auditory Brainstem Responses (II): Maturational, Gender and Aging Effects in C57Bl/6J and CBA/CaJ MicePaul Allen1, John Housel2, Jason Moore1, William O'Neill1,2, Peter Rivoli1, James Ison1
1Department of Brain & Cognitive Sciences, University of Rochester;2 Dept of Neurobiology & Anatomy, University of Rochester School of Medicine and Dentistry; Rochester, NYARO 2005
433
Introduction
CBA/CaJ: (710 recordings, 388 from Males, 322 from Females)
C57Bl/6: (484 recordings, 244 from Males, 240 from Females)
Auditory brainstem response (ABR)
Routinely measured in conjunction with behavioral, electrophysiological or histological experiments
For methods see presentation 437
Multiple ABRs were accepted for an animal only if there was a minimum of 60 days between recordings
Animals undergoing drug treatment etc. are excluded
Superthreshold ABR is assessed via signal to noise
S/N ratio calculated from the RMS of 2kHz high-pass filtered waveforms
RMS windows: Pre-response = 0.75-1.5 ms, Evoked Response = 1.5-10 ms
S/N calculated for a subset of mice (using TDT System II apparatus)
CBA/CaJ (N=259, 145 Males and 114 Females)
C57Bl/6 (N=99, 39 Males and 60 Females) Supported by NIA Grant #AG09524 and The Schmitt Program on Integrative Brain Research
Subjects and Methods
CBA/CaJ
3 6 12 24 32 480
10
20
30
40
50
60
70
80
90
15-22 mo23-27 mo28-34 mo
7-14 mo
1 mo
SEM
Frequency (Hz)
Leve
l (dB
SP
L)
Age distribution of CBA mice
0 4 8 12 16 20 24 28 32 360
25
50
75
100
125
150
175
Female
Male
Age (mo)
N
Age distribution of C57 mice
0 1 2 3 4 5 6 7 8 9 10 11 120
20
40
60
80
100
120
Female
Male
Age (mo)
N
1 2 3 4 5-6 7-14 15-22 23-27 28-34-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
-0.0
0.1
0.2
0.3
0.4
0.5
0.6 3 kHz
12 kHz24 kHz32 kHz48 kHz
6 kHz
Male Advantage
Female Advantage
SEM
Age (mo)
AB
R R
MS
Rat
io
1 2 3 5 7 8 10 120
10
20
30
40
50
60
70
80
90
100
6 kHz Male
3 kHz Female
48 kHz Female48 kHz Male
3 kHz Male
6 kHz Female
Age (Months)
AB
R t
hres
hold
(dB
SP
L)
SEM
C57Bl/6J
3 6 12 24 32 480
10
20
30
40
50
60
70
80
90
100
1 mo
3 mo
6 mo8 mo
12 moSEM
Frequency (Hz)
Leve
l (dB
SP
L)
1 2 3 5 7 8 10 12
12 kHz Female
16 kHz Female16 kHz Male
32 kHz Female
24 kHz Female24 kHz Male
32 kHz Male
0
10
20
30
40
50
60
70
80
90
100
12 kHz Male
Age (Months)
AB
R t
hres
hold
(dB
SP
L)
SEM
1 2 3 4 5-6 7-14 15-22 23-27 28-340
10
20
30
40
50
60
70
80
12 kHz Male12 kHz Female
32 kHz Female32 kHz Male
24 kHz Male24 kHz Female
Age (Months)
AB
R t
hres
hold
(dB
SP
L)
SEM
1 2 3 4 5-6 7-14 15-22 23-27 28-340
10
20
30
40
50
60
70
80
90
3 kHz Female3 kHz Male
6 kHz Female
48 kHz Female48 kHz Male
6 kHz Male
Age (Months)
AB
R t
hres
hold
(dB
SP
L)
SEM
C5712 kHz, 90 dB SPL
1 2 3 4 5 6 7 8-3.0×10-06
-2.0×10-06
-1.0×10-06
-2.3×10-13
1.0×10-06
2.0×10-06
3.0×10-06
4.0×10-06
5.0×10-06
6.0×10-06
7.0×10-06
Early: 2-4 moMiddle: 4-6 moLate: 6-8 mo
Time (ms)
Vo
ltag
e
2-4 mo
1 2 3 4 5 6 7 8
-2.0×10 -6
0
2.0×10 -6
4.0×10 -6
6.0×10 -6 MaleFemale
4-6 mo
1 2 3 4 5 6 7 8
-2.0×10 -6
0
2.0×10 -6
4.0×10 -6
6.0×10 -6
MaleFemale
6-8 mo
1 2 3 4 5 6 7 8
-2.0×10 -6
0
2.0×10 -6
4.0×10 -6
6.0×10 -6 MaleFemale
12 kHz, 90 dB SPLCBA12 kHz 90 dB SPL
1 2 3 4 5 6 7 8-4.0×10-6
-2.0×10-6
0
2.0×10-6
4.0×10-6
6.0×10-6
Young: 2-4 moMiddle-aged: 11-13 moOld: 23-25 mo
Time (msec)
AB
R (
V)
0
2-4 mo
1 2 3 4 5 6 7 8
-4.5×10 -6
-3.0×10 -6
-1.5×10 -6
1.5×10 -6
3.0×10 -6
4.5×10 -6
6.0×10 -6
7.5×10 -6
0
MaleFemale
0
11-13 mo
1 2 3 4 5 6 7 8
-4.5×10 -6
-3.0×10 -6
-1.5×10 -6
1.5×10 -6
3.0×10 -6
4.5×10 -6
6.0×10 -6
7.5×10 -6
0
MaleFemale
0
23-25 mo
1 2 3 4 5 6 7 8
-4.5×10 -6
-3.0×10 -6
-1.5×10 -6
1.5×10 -6
3.0×10 -6
4.5×10 -6
6.0×10 -6
7.5×10 -6
0
MaleFemale
Changes in ABR Waveforms with Age Changes in ABR Waveforms with Hearing-loss
0 1 2 3 4 5 6 7 8 90
1
2
3
4
5
6
7
83 kHz
12 kHz24 kHz32 kHz48 kHz
6 kHz
Age (mo)
AB
R R
MS
Rat
io
SEM
2 3 4 5 6 7 8
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
-0.0
0.1
0.2
0.3
0.4
0.5
0.6
3 kHz
12 kHz24 kHz32 kHz48 kHz
6 kHz
Female Advantage
Male Advantage
SEM
Age (mo)
AB
R R
MS
Rat
io d
iffe
ren
ce
1 2 3 4 5-6 7-14 15-22 23-27 28-34
1
2
3
4
5
63 kHz
12 kHz24 kHz32 kHz48 kHz
6 kHzSEM
Age (mo)
AB
R R
MS
Rat
io
0 1 2 3 4 5 6 7 8 9 10
-5.0×10 -6
-2.5×10 -6
0
2.5×10 -6
5.0×10 -6
Pre-Response RMS: 4.4125e-07Response RMS: 3.1721e-08Ratio: 13.9103
rawfiltered
Time (ms)
AB
R (
V)
22 M - 17 F41 M - 22 F9 M - 9 F27 M - 21 F11 M - 10 F35 M - 35 F
Leve
l (dB
SP
L)Le
vel (
dB S
PL)
2 mo 5-7 mo 8-14 mo 15-22 mo 23-27 mo 28-34 mo
16 M - 20 F 19 M -17 F 1 M - 8 F 3 M - 7 F 0 M - 8 F
Leve
l (dB
SP
L)Le
vel (
dB S
PL)
2 mo 3 mo 5 mo 7 mo 8 mo
ABR Thresholds from 1 to 30 Months of Age ABR Thresholds: 1 to 12 Months of Age
ABR Ratio Plots
Difference in Ratio
Male - Female
ABR Ratio Plots
Difference in Ratio
Male - Female
Changes in Superthreshold ABR with Hearing-lossAging-related Changes in Superthreshold ABR
ABR Ratio vs Age
90dB SPL
Difference in Ratio
Male - Female
ABR Ratio vs Age
90dB SPL
Difference in Ratio
Male - Female
CBA/CaJ and C57BL/6J mice provide useful models for contrasting rapid degenerative vs. slow age-related hearing loss. The descriptions of ABR hearing measures in these mice are mostly obtained in small groups (save for Li and Borg, 1991), and concerned with thresholds (save for Hunter and Willott, 1987). Our colony at the University of Rochester provides these mice to investigators focused on age-related changes in complex auditory processing. Both threshold and superthreshold ABR measures are taken on many mice at ages that meet the special needs of particular protocols. Here we describe ABR measures collected over 6 years, in a total of 570 CBA mice (267F, 303M) and 353 C57 (161F, 192M), most born in the vivarium from Jackson Lab breeding stock. The youngest mice for which records are available were 27 days of age while the oldest mice were 1046 days of age for the CBA (n = 2) and 787 days of age for the C57 (n=2). The data we present are grouped in age bins providing sufficiently large samples of males and females to minimize potential cohort and procedural differences across time.
• Reduction in P1 amplitudes (as seen for 12kHz, 90dB SPL)
• Lengthening of Inter-peak intervals
(Note that wave forms are aligned on P1)
• Subtle changes in ABR waveform with age
Change in appearance of P1a/N1 complex
• No sex effect on ABR waveforms
• No threshold loss (and possible maturational gain?) up to 14 mo of age
• Progressive loss, equal across frequency, beyond 14 mo of age
• No systematic sex differences
• Superthreshold S/N ratio plots show substantial decline with age in first year of life, despite negligible threshold changes
Central neural aging?
Artifact of changes in head size, or dielectric properties of cranium?
• Possible weak female advantage seen in S/N color plots up to 22 months
• S/N ratios for 90 dB highlight the progressive decline into old age and lack of systematic sex differences with age and frequency
Left: “Classic” frequency across age Right: Age effect across frequency 1) Initial slow loss for all frequencies, then delayed abrupt loss, higher first2) Old females are slightly more sensitive to low frequencies
Reduction in P1 amplitude (shown for 12kHz, 90 dB)(Note that waveforms have been aligned on P1)
ABR waveforms change with hearing-loss
Inter-peak intervals remain stable (except P2, P4)
Females have slightly larger ABR peaks (Head size?)
Superthreshold S/N ratios show progressive high frequency hearing loss in parallel with the elevated ABR thresholds. The 90 dB S/N data show a progressive decline with age for all frequencies
Possible female advantage is seen in S/N ratios above threshold, and is consistent with threshold data
The initial age-related gradual hearing loss across frequencies is consistent with, e.g., Hequembourg & Liberman, (2001), but the data favoring female over male inconsistent with Willott & Bross (2004) or Henry (2002).